Top PDF Modeling and nonlinear adaptive control of an aerial manipulation system

Modeling and nonlinear adaptive control of an aerial manipulation system

Modeling and nonlinear adaptive control of an aerial manipulation system

In this thesis, an aerial manipulation system (AMS) consisting of a quadrotor with a 2-DOF manipulator was designed and constructed. The entire mathemat- ical model of the system that incorporates the coupling between the quadrotor and robotic arm, and the physical interaction with the environment was derived through the Euler-Lagrange formulation. Based on this mathematical model, a nonlinear adaptive control framework was developed. It was applied on a high fidelity AMS model which includes mass and inertia uncertainties, wind distur- bances, and measurement noises. In order to control the positional dynamics of the AMS in the presence of mass uncertainty and reaction forces, model reference adaptive control (MRAC) was utilized. Using the command signals generated by the MRAC and making small angle approximations, desired attitude angles were calculated analytically for the low-level controller. Attitude dynamics of the quadrotor and 2-DOF manipulator dynamics were combined as a 5-DOF fully actuated system. Nonlinear adaptive control was implemented for this 5-DOF rotational dynamics where uncertainties in inertias were considered.
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Adaptive Control for Nonlinear Singular Systems

Adaptive Control for Nonlinear Singular Systems

Abstract. Nonlinear singular systems present a general mathematical framework for the modeling and controlling of complicated systems, however the complex nature of this type of systems causes many difficulties in control strategy. In this paper, a model reference control approach is addressed for nonlinear affine singular systems. First, a basic control system is proposed based on the Lyapunov stability theorem so that nonlinear singular system can asymptotically track the desired linear reference model. After that, in the second design, it has been considered that systems’ parameters are unknown and two adaptive approaches are investigated. For better illustration, simulation has been done and the results show the tracking performance for both presented control systems.
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Modeling And Control For Robotic Assistants: Single And Multi-Robot Manipulation

Modeling And Control For Robotic Assistants: Single And Multi-Robot Manipulation

This work then considers the task of a robot assistant preparing an experiment for collaboration with wet-laboratory research scientists. The task is to efficiently pour fluid between an open pouring and a receiving container. An efficient pour is characterized as both quick and precise. It is assumed that there is no spillage and that the properties of the poured fluid are known. The contributions of this work for this task are two fold. In the case where the geometry of all containers are known, and the receiver can be observed during the pour, an analytical solution is provided which considers the expected flow-rate of the fluid given both containers geometry. With this analytical solution, the robot is able to pour very quickly and precisely leveraging a hybrid controller that both ensures steady flow and considers the system dynamics in order achieve the desired receiver volume. In the case where the geometry of the pouring container is not known analytically, it is assumed that the geometry can be approximated by an initial external scan of the container. While for simplicity this work considers symmetric pouring containers, this is not a limitation as long as a distance metric can be defined between container geometries. During the pour only the receiving container is observed, and the system dynamics must be adjusted based on an initial estimate obtained from a single scan of the pouring container geometry. The main contribution in this case is that both classical system identification and learning are used simultaneously to predict the pouring container behavior. This prediction is a necessity because the time delay between the rotational velocity control input of the pouring container and the observed volume in the receiver is substantial for certain pouring container geometries. This predicted model for the pouring container is then used in a hybrid controller to achieve the control objective by anticipating the nonlinear dynamics. This is implemented on the Rethink Robotics Sawyer and KUKA intelligent industrial work assistant (iiwa) manipulators.
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Preliminary Design of Robust Adaptive Control Laws for an Aerial Manipulator

Preliminary Design of Robust Adaptive Control Laws for an Aerial Manipulator

One final control method to discuss for lightweight manipulators is MRAC con- trol. MRAC control is fairly straightforward to implement in two-link manipulators due to the ideal system dynamics at a set trajectory point being relatively easy to find [33]. This provides a relatively simple calculation, unlike the high compu- tational load required to calculate the actual system dynamics in real time [33]. However, many modelling assumptions must be made, such as known payload mass and perfect joint structure, resulting in a large error between the actual and ideal system responses that must be corrected by the MRAC algorithm. Furthermore, the linearization of the ideal system may not be valid for all manipulator configurations, due to straying too far from the operating point [50]. This in turn limits the valid operating range of the manipulator, reducing its efficacy in the tasks asked of it. Hence, ASMC is the much more popular control algorithm for robotic manipulation [50].
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Nonlinear and Fault-tolerant Control Techniques for a Quadrotor Unmanned Aerial Vehicle

Nonlinear and Fault-tolerant Control Techniques for a Quadrotor Unmanned Aerial Vehicle

linearization is popular as well in other areas. Oriolo et al [12] propose an implementation of FLC in wheeled mobile robots tracking task in [10]. From [12], a good trajectory tracking performance of PUMA 560 robot manipulator is achieved by using discontinuous feedback linearization rather than a PID control, which makes the controller more suitable for an electrically driven high speed robot manipulator. Fuzzy control is a powerful tool for handling system uncertainties and noises, and feedback linearization needs an inversion of the system. When the system and environment are uncertain, feedback linearization control alone might not be suitable enough as the controller due to its sensitivity to modeling errors, uncertainties, and noises, and thus reference [13] provides a possible solution by the combination of these two methods. In reference [14], a popular pendulum problem is solved by an input-output feedback linearization cascade controller.
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The Research on Adaptive Control Modeling of a Liquid Fertilizer Spreader

The Research on Adaptive Control Modeling of a Liquid Fertilizer Spreader

hydraulic pump. In order to develop control algorithms to achieve the above objective, we must first develop a dy- namic model for the spreader. Specifically, we need a relationship between the input, i.e. the auger speed and the gate opening size, and the output, i.e. the material discharge rate. Recall that the material is a highly inho- mogeneous mix of liquids and solids with unknown per- centage of each phase. The weight and viscosity of the material affect the dynamics of the hydraulic system that drives the auger. As the spreading proceeds, the amount of material remaining in the tank changed. All these fac- tors attribute to a nonlinear and time-varying dynamics of the spreader. As discussed in Section 1, analytical mod- eling of such a system is a difficult task. In this study, we propose to develop an on-line numerical model of the input-output relationship, known as the system transfer function. The controller of on-line model has an Atmel processor 89S51 with 33MHz frame rate. It communi- cates with a laptop computer via RS232 at 9600 baud. This controller can interface with and control a wide range of equipment including variable rate applicators for precision agriculture. The on-line system model fits the experimental data to a pre-determined numerical model with undetermined coefficients. A very common numeri- cal model can describe a large.
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Adaptive nonlinear MPPT control for PV 
		system with resonant DC/DC converter

Adaptive nonlinear MPPT control for PV system with resonant DC/DC converter

Various equivalent circuits have been reported in the literature for PV cell modeling. For instance, there is one-diode, two-diode and three-diode model [7, 18]. The equivalent circuit of two-diode and three-diode model can be used to improve the PVG model accuracy [18]. However, due to their strongly nonlinear character, it is very difficult to exploit these model for the control law design [7]. Therefore, the one-diode model is adopted in this study, since it provides sufficient accuracy besides an easier adaptation to the control design. Figure-3 depicts the corresponding electrical circuit [19].
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Nonlinear adaptive algorithm for active noise control with loudspeaker nonlinearity

Nonlinear adaptive algorithm for active noise control with loudspeaker nonlinearity

In this work, a novel nonlinear modeling technique in NANC is proposed to overcome the drawbacks of NLFXLMS algorithm. Sequentially, the proposed model is used to develop a controller algorithm based on Tangential hyperbolic function (THF). The work is restricted to single input, single output (SISO) ANC system. The feedforward strategy is used to control the noise at the observer [30]. All the transfer function and filters are assumed to be linear except the loudspeaker which is represented by a memory less saturation nonlinearity. The work involves designing and simulating the proposed modeling technique. At the control stage, an alternative THF-NLFXLMS algorithm is proposed and compared with NLFXLMS and FXLMS when ANC system deals with loudspeaker nonlinearity. Figure1.1, illustrates the research scope which is covered in this argumentation.
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Adaptive neuro-fuzzy model with fuzzy clustering for nonlinear prediction and control

Adaptive neuro-fuzzy model with fuzzy clustering for nonlinear prediction and control

analyses are much more difficult. This paper presents the use of neuro-fuzzy networks as means of implementing algorithms suitable for nonlinear black-box prediction and control. In engineering applications, two attractive tools have emerged recently. These two attractive tools are: the artificial neural networks and the fuzzy logic system. One area of particular importance is the design of networks capable of modeling and predicting the behavior of systems that involve complex, multi-variable processes. To illustrate the applicability of the neuro-fuzzy networks, a case study involving air-fuel ratio is presented here. Air-fuel ratio represents complex, nonlinear and stochastic behavior. To monitor the engine conditions, an adaptive neuro-fuzzy inference system (ANFIS) is used to capture the nonlinear connections between the air-fuel ratio and control parameters such manifold air pressure, throttle position, manifold air temperature, engine temperature, engine speed, and injection opening time. This paper describes a fuzzy clustering method to initialize the ANFIS.
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Adaptive Fuzzy Dynamic Sliding Mode Control of Nonlinear Systems

Adaptive Fuzzy Dynamic Sliding Mode Control of Nonlinear Systems

Two phenomena can produce chattering: switching of input control signal and the large amplitude of this switching (switching gain). To remove the switching of input control signal, dynamic sliding mode control (DSMC) is used. In DSMC switching is removed due to the integrator which is placed before the plant. However, in DSMC the augmented system (system plus the integrator) is one dimension bigger than the actual system and then, the plant model should be completely known. To overcome this difficulty, a fuzzy system is employed to identify the unknown nonlinear function of the plant model and then, a robust adaptive law is developed to train the parameters of this fuzzy system. The other problem is that the switching gain may be chosen unnecessary large to cope on the unknown uncertainty. To solve this problem, another fuzzy system is proposed which does not need the upper bound of the uncertainty. Moreover, to have a suitable small enough switching gain an adaptive procedure is applied to increase and decrease the switching gain according to the system circumstances. Then, chattering is removed using the DSMC with a small adaptive switching gain (ASG). As a case study, nonlinear chaotic Duffing-Holmes system is selected.
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Active steering system based on nonlinear control system

Active steering system based on nonlinear control system

Moreover, intelligent based techniques such as fuzzy logic, neural network and genetic algorithm have been applied to the active steering system. M.K.Park et al. (1996) presented a fuzzy-rule-based cornering force estimator to avoid using an uncertain highly nonlinear expression, and neural network compensator is additionally utilized for the estimator to correctly find cornering force. The result indicated that the proposed control system is robust against the uncertainty in vehicle dynamic model disturbances such as a side wind gust and road conditions.

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Dynamic Modeling and Adaptive Control of a Cable-suspended Robot

Dynamic Modeling and Adaptive Control of a Cable-suspended Robot

Control of this kind of robots has attracted the attention many researchers, mostly because of its great impact on the efficiency of the robotic systems. Several control methods have been proposed for parallel manipulators. However, only a few of the proposed topologies can be implemented in cable driven parallel manipulators. Most of the proposed control schemes are based on dynamic model of the robot. Representatives of such inverse dynamic control schemes can be viewed in [3], [4] and [5]. Moreover, Fang et al. [6] have proposed a motion control scheme on cable length coordinates, De Luca et al. [7] have presented a proportional and derivative (PD) controller with on-line gravity compensation for robots with elastic joints, Ryeok and Agrawal [8] developed a method for control based on feedback linearization, Ryeok et al. [9] have designed a two level controller for a helicopter carrying a payload using a cable suspended robot, Zi et al. [10] implemented inverse dynamic control using fuzzy neural network type 2 to these robots, Oh et al. [11] used robust control for two-stage cable robots, Oh and agrawal [ 12-16] proposed Lyapunov Based PD-like control and Nonlinear Sliding Mode control for cable-based robots , and Duchaine et al. [17] have proposed an approach to the control of manipulators using a computationally efficient-model-based predictive control scheme. This paper presents a different control topology examined for possible implementation on cable-suspended robots using an adaptive control scheme. The proposed controller structure guarantees fully tension forces on the cables, in a more trusted fashion, and is capable to fulfill the stringent positioning requirements for these type of manipulators.
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Modeling and Implementation of Adaptive Control Technique on a TRMS Model

Modeling and Implementation of Adaptive Control Technique on a TRMS Model

Abstract: Twin Rotor Multi-input-multi-output System (TRMS) resembles a desktop version of a non-linear helicopter model. It consists of two rotors namely tail rotor and main rotor. A model based on first principle modeling approach is designed in MATLAB Simulink environment. An adaptive control scheme based on Model Reference Adaptive Systems (MRAS) theory is implemented for tracking the desired trajectory with changing system parameters and disturbances. MRAC based Lyapunov Theory is used to adjust the gains for guaranteeing stability and converges the error to zero under stochastic conditions. The output of the TRMS Model is far better for MRAC based Lyapunov Approach than compared to PID. The main objective of this project is to stabilize the non-linear TRMS model.
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Study on Learner Modeling in Adaptive Learning System

Study on Learner Modeling in Adaptive Learning System

For the estimation of preferences, it divided into two steps which are initial estimation and dynamic estimation. We have to pretest the learners’ interests before them using the system for learning and also initialize learner’s interests. With the proceed of learner’s learning activities, we can discover learner’s interests. Then correct and maintain those values through data mining about the data of learners’ searching concepts, browsing websites’ types and topics of discussions. For the initializing values, we can gather user’s interests information through user’s registration forms or scale, and use direct or indirect matching methods to process those original data to acquire the initial values. For dynamic values, it concerns about learner’s learning procedure information and historical testing information. Then processes the acquired values through data mining model to obtain the needed data.
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Adaptive Control Schemes for a class of Hammerstein-Wiener nonlinear systems

Adaptive Control Schemes for a class of Hammerstein-Wiener nonlinear systems

This paper is organized as follows. In Section 2, the Bai's system for which we are developing the adaptive controler is presented. In Section 3 the proposed technique using the approximate inverse method is given. In Section 4 the proposed technique using the estimate of the plant noise is presented and Section 5 includes illustrative example and the simulation results for the developed technique.

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A New Simulation Modeling for Nonlinear Current Control in Single Phase Grid Connected PV System

A New Simulation Modeling for Nonlinear Current Control in Single Phase Grid Connected PV System

The issue of energy saving & energy conservation is prime concern in electrical power system. Researchers start taking interest in efficient use of renewable energy sources & improvement in its implementation techniques. Apart from the different renewable energy sources, photovoltaic systems are prime renewable energy source. PV cells are pollution & noise free sources of energy. Due to increasing demand in energy, government in developing countries like India also shown keen interest to individual solar power plants. PV system used in a solar cell connected in array like structure. Major advantage of integrating PV system in array format is that they can be interfaced with energy converter system easily. The use of PV system can be found in both AC converters as well as DC inverters. The topology has easier controller design as the two converters have independent control goals and architectures. Yet, the system has poor efficiency, due to a large number of devices, excessive size, heavy weight, and high cost. [1]
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ADAPTIVE TRAFFIC LIGHT CONTROL SYSTEM

ADAPTIVE TRAFFIC LIGHT CONTROL SYSTEM

Our objective is to define a basic scenario in order to understand various problems faced by traditional traffic light control system and to provide technical solution to amend these adversities to improve the speed of transport. Congestion due to vehicular traffic intersection at junction is one the major issues to be considered. To overcome such issues an intelligent traffic signal network is required. Adaptive traffic light control (ATLC) system deals with manipulation of the green light timings according to the number of vehicles present at each entry. Our system consists of ARM Cortex based KL25Z controllers, Laser Sensors and Xbee transmitters- receivers. The supporting program of our system is compiled in ‘mbed portal’ and the simulation is carried out with the help of ‘Proteus’ application. Our system ensures the effective use of allocated delays to deal with these adversities.
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Real World Modeling and Nonlinear Control of an Electrohydraulic Driven Clutch

Real World Modeling and Nonlinear Control of an Electrohydraulic Driven Clutch

During the last phase of gear shift procedure, just after the gear changed and gearbox synchronized, the clutch is going to lock so that the torque can flow from the engine to the wheels. After changing gear, there are two different speeds on the flywheel and the clutch plate and this speed difference have to be ironed out, i.e. the clutch synchronizes. As mentioned, there have been researches based on gear shifting just by engine control or Integrated Power Control scheme [14- 18]. These approaches are feasible mainly in hybrid drive-trains in which the difference can helpfully be lowered by adjusting the speed difference “externally” i.e. by engine or electric motor actuation. However, in general case of control of an AMT, what the present study aims at, this difference has to be mostly disappeared by making frictional contact which clutch plate produces while it touches flywheel. In other words, clutch synchronization would synchronize the speeds by itself. This makes the control program much more complicated as an appalling shuffle would emerge by an unsuccessful engagement.
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Nonlinear observer based PI sliding surface of adaptive sliding mode control for boost converter in PV system

Nonlinear observer based PI sliding surface of adaptive sliding mode control for boost converter in PV system

The block diagram of proposed system is illustrated in Figure 1 and system parameters is described in Table 1. The system parameters consist of boost converter, nonlinear observer, controller, and reference model parameter. Boost converter parameters are calculated based on continuous conduction mode (CCM). The method to select boost converter parameters can be found in [18]. The selection of nonlinear observer parameters are based on (11) and (16). Eq. (11) mentioned that Lyapunov function has to be positive definite, thus adaptive law gains are selected to be positive definite. Eq. (16) are obtained to be negative definite, thus in order to ensure (16) to be negative definite, the observer gains has to be selected into positive definite. Therefore, in Table 1, adaptive law gains and observer gains are selected to be positive definite. The selection of proposed controller paramaters follows (4) and (21). The photovoltaic rating is provided in Table 2. The polycrystalline solar panel is used for this paper. The numerical simulation is conducted to prove the effectiveness of the proposed method. The system will be tested under six scenarios, which in detail will be described in Section 3.
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Modeling and Control of Nonlinear Process Using Robust and Soft Controllers

Modeling and Control of Nonlinear Process Using Robust and Soft Controllers

ABSTRACT: Level control in a hemispherical tank is a challenging task in process industries due to nonlinear variation of level with height. The need for an accurate and appropriate online or off line model to control such nonlinear process is on huge demand to avoid process complications in practical applications such as oil refineries, dye industries etc. In this work, a hemispherical tank of 40 liter capacity was subjected to dynamic analysis and level measurement was done using an on-line Honeywell capacitance sensor. Modeling was performed using first principle of mathematics, open loop analysis and Skogestad technique. The various models were validated using standard performance indices and it was observed that Skogestad model performed better with minimum model error. Real time level control was implemented using various robust, adaptive and intelligent controllers such as Smith, IMC and NMPC. The performance of the controllers was evaluated using time domain specifications. Error analysis was also performed and it was observed that NMPC and IMC controller outperformed the other controllers.
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