One of the basic issues in the navigation of autonomous mobile robots is the obstacle avoidance task that is commonly achieved using a reactive control paradigm where a local mapping from perceived states to actions i...
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One of the basic issues in the navigation of autonomous mobile robots is the obstacle avoidance task that is commonly achieved using a reactive control paradigm where a local mapping from perceived states to actions is acquired. A control strategy with learning capabilities in an unknown environment can be obtained using reinforcement learning where the learning agent is given only sparse reward information. This credit assignment problem includes both temporal and structural aspects. While the temporal credit assignment problem is solved using core elements of the reinforcement learning agent, solution of the structural credit assignment problem requires an appropriate internal state space representation of the environment. In this paper, a discrete coding of the input space using a neural network structure is presented as opposed to the commonly used continuous internal representation. This enables a faster and more efficient convergence of the reinforcement learning process.
In this paper, the design of available bit rate (ABR) congestion control in ATM (asynchronous transfer mode) networks is considered. The goals of congestion control are high link utilization, low cell loss, and low ne...
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In this paper, the design of available bit rate (ABR) congestion control in ATM (asynchronous transfer mode) networks is considered. The goals of congestion control are high link utilization, low cell loss, and low network delay. Various algorithms for congestion control can be found in the literature. Most of them are based on a network model, which is assumed to be known. In this paper a recursive least square (RLS) algorithm for on-line identification of the network model is implemented and combined with a generalized predictive controller (GPC) and with an I-controller based on the Smith predictor. Simulations were carried out to prove the effectiveness of the proposed algorithms.
A laboratory model for experimental investigations of the rubber-asphalt sliding pair has been designed with the purpose of better understanding of dynamic behavior of the friction force in the contact patch between t...
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This work presents dominant pole design (DPD) methodology, one MATLAB implementation of DPD and its usage. DPD for PI and PID controllers is derived, and on this basis MATLAB toolkit for three-pole method (3PM) has be...
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This work presents dominant pole design (DPD) methodology, one MATLAB implementation of DPD and its usage. DPD for PI and PID controllers is derived, and on this basis MATLAB toolkit for three-pole method (3PM) has been developed. The least squares procedure for finding functional dependence of PID controller parameters on process parameters is described. This least squares procedure has been applied to the first order process with dead time (FODT) obtained functional dependence, expressed through tuning formulas, is presented. Performance of PID controller tuned with 3PM tuning formulas is compared to the performance of PID controller tuned with integral criteria derived tuning formulas. Observed characteristics of DPD method are given at the end of the paper.
The design of current and speed controllers remains to a large extent a mystery to many engineers in the motor drives field. An attempt is made in this paper to simplify the design of the current and speed controllers...
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The design of current and speed controllers remains to a large extent a mystery to many engineers in the motor drives field. An attempt is made in this paper to simplify the design of the current and speed controllers using Bode plots. This paper outlines the theoretical background behind the techniques of symmetric optimum and dominant time constant compensation methods. The techniques are compared and contrasted using the overshoot and phase margin criteria. An application of these techniques to controller design for permanent magnet brushless DC motor (PMBDCM) drive system is made and verified with simulation. In order to apply these techniques to PMBDCM drive for the design of the current and speed controllers, the model of the motor drive is given for the benefit of the reader. The current and speed controller synthesis of a PMBDCM drive is achieved with the presented technique. Simulation results demonstrate for reference (current or speed) changes, symmetric optimum and dominant time compensation methods perform similarly. But for a load torque disturbance, the adverse effect on the speed is compensated faster only with the symmetric optimum method.
Constraint programming (CP) systems are useful for solving real-life combinatorial problems, such as scheduling, planning, rostering and routing problems. The design of modern CP systems has evolved from a monolithic ...
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Constraint programming (CP) systems are useful for solving real-life combinatorial problems, such as scheduling, planning, rostering and routing problems. The design of modern CP systems has evolved from a monolithic to an open design in order to meet the increasing demand for application-specific customization. It is widely accepted that a CP system needs to balance various design factors such as efficiency versus customizability and flexibility versus maintenance. This paper captures our experience with using different software engineering approaches in the development of constraint programming systems. These approaches allow us to systematically investigate the different factors that affect the performance of a CP system. In particular we review the application of reuse techniques, such as toolkits, framework and patterns, to the design and implementation of a finite-domain CP system.
To support all phases of an agile modular manufacturing machine life cycle with CAE and Virtual Manufacturing tools, a number of different engineering applications (e.g. specialist software based tools) are typically ...
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To support all phases of an agile modular manufacturing machine life cycle with CAE and Virtual Manufacturing tools, a number of different engineering applications (e.g. specialist software based tools) are typically used for design, simulation, analysis, programming, control and monitoring of a machine. These applications mainly exist today as small applications islands where each of them manages their own data. When a manufacturing machine is designed, simulated, programmed, analyzed, tested, or operated, the information, connected to that specific machine, used and generated by each application island is stored separately by each application. These application islands often use different storage technologies. Each one of the applications has an information structure to separate the information connected to each machine; however, they do not necessarily use the same information structure. Another issue concerning these applications is the functionality that is implemented in them to manage information; namely, processes such as store, retrieve, search, permissions, etc. The functionality for one process is the same in all applications that has the process implemented. But the implementation of the process functionality may differ, due to misinterpretation of the functionality specification and regular implementation bugs, which could lead to problem with integrity and consistency of the data. Applications that make use of newer information technologies, such as databases and software development tools can simplify the implementation of the functionality but each application still has to implement their own version of the functionality. This paper presents a research investigation focused on the development of a distributed integration platform that supports the whole life cycle of agile modular machine systems, which includes the design, simulation, programming, analysis, machine operation and re-configuration. The environment supports distributed management and s
Message-passing programming interfaces are widely used when programming parallel applications. Systems such as PVM and MPI have been successful at providing the basic capabilities needed to implement parallel applicat...
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