Heuristic Control Research Articles

A heuristic feedback control theory based interactive expert system – RSCD

In this paper, we focus on the difficulties of resource recycling problems relating to the used Iron and/or Aluminum cans. Based on the feedback control theory and combining with micro-chip processor, sensors, phonic chip, oil-compressor and mechanism technology, we design an interactive resource recycling Expert System –“Recycling Squeezed Cans Device” (RSCD) and the proposed interactive RSCD is an automaton device and achieves the following attractive functions: (1) Automatic guiding and detecting system, (2) Security protection system, (3) Automatic classification system, (4) Automatic squeezing system, (5) Automatic distributed collection system, (6) Automatic refund system. We design a heuristic feedback control algorithm imbedded in processor chip and the proposed interactive RSCD has the following special features: the Automatic guiding and detecting system using phonic chip associated with sensors and panel light indicator can easily lead users to operate the RSCD, the Security protection system using sensors associated with electromagnetic switches and safety mechanism designs can protect users harmless and the RSCD as well, the Automatic classification system using sensors associated with mechanic device and the design relating to rotating stepping motor can precisely discriminate whether the recycling used cans material belongs to metal or nonmetal type, and moreover, classify Iron or Aluminum type, the Automatic squeezing system using oil-compressor associated with sensors, and the design as to the compressing device can rapidly squeeze the recycling used cans into under about 1/5 of its original volume, the Automatic distributed collection system using sensors associated with stepping motor, micro-switches, and the design concerning the collection device can precisely distributed collect the recycling compressed cans into two different cans collection tanks, and the Automatic refund system using micro-switches associated with counter, and the design as to the rotating withdrawing device quickly give back the desired refunds. We install the proposed interactive RSCD in several different areas in public and make numerous simulations, the test results show that the proposed interactive RSCD is efficient for handling the resource recycling problems as to the recycling used Iron and/or Aluminum cans.

Opportunistic spectrum access for energy-constrained cognitive radios

This paper considers a scenario in which a secondary user (SU) opportunistically accesses a channel allocated to some primary network (PN) that switches between idle and active states in a time-slotted manner. At the beginning of each time slot, SU can choose to stay idle or to carry out spectrum sensing to detect the state of PN. If PN is detected to be idle, SU can carry out data transmission. Spectrum sensing consumes time and energy and introduces false alarms and mis-detections. The objective is to dynamically decide, for each time slot, whether SU should stay idle or carry out sensing, and if so, for how long, to maximize the expected reward. We formulate this as a partially observable Markov decision process and prove important properties of the optimal control policies. Heuristic control policies with low complexity and good performance are also proposed. Numerical results show the significant performance gain of our dynamic control approach for opportunistic spectrum access.

A Distributed Heuristic for Energy-Efficient Multirobot Multiplace Rendezvous

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> We consider the problem of finding a set of trajectories for a heterogeneous group of mobile robots, such that a single service robot can rendezvous with every other member of the team in a prescribed order, and the total travel cost is minimized. We present a simple heuristic controller that runs independently on each robot, yet is guaranteed to achieve an approximation to global solution in bounded time linear in population size. Simulation experiments empirically show that the method finds approximated solutions of near-optimal quality on average. </para>

Dynamic simulation for internally heat-integrated distillation columns (HIDiC) for propylene–propane system

This paper reports a dynamic simulation study of the internally heat-integrated distillation column (HIDiC) using equilibrium-based models. First, three different HIDiC structures, i.e. an ideal HIDiC, a HIDiC with a pre-heater, and a HIDiC with a reboiler, are analyzed by control degrees of freedom (DOF). The reboiler is considered to be a necessary part of the HIDiC from DOF analysis, thermodynamic analysis, and engineering judgment. Then, a heuristic HIDiC control configuration including a bottoms reboiler control is proposed. A modular structured simulator for dynamic distillation columns using MESH equations is developed. The simulator also considers: (1) variable column pressure on each tray of the rectifying section, (2) dynamic vapor holdup, and (3) dynamic energy balance. In addition, the SRK equation of state is employed for estimating thermodynamic properties. A typical medium-pressure HIDiC for separation of propylene and propane explored by Olujic et al. [Olujic, Z., Sun, L., de Rijke, A., & Jansens, P. J. (2006). Conceptual design of an internally heat-integrated propylene–propane splitter. Energy, 31, 3083] is adopted as numerical examples for dynamic simulation studies.

Node Mobility Control and Capacity in Wireless Ad Hoc Networks

The end-to-end throughput of stationary random wireless networks is scaled by Θ (1nlogn). This throughput scale can be changed into Θ(1) by making the flows to be local flow patterns. By exploiting the controllable mobility of mobile nodes in order to reduce the path length, it is possible to achieve the constant scale end-to-end capacity regardless of the node density. The shortened path length at the resultant network reduces the traffic delay and improves the energy efficiency at the same time. The mobility control for the constant throughput scale can be formulated as a optimization problem, and we propose a simple heuristic mobility control algorithm based on the analysis and the problem formulation. Extensive simulations show that the proposed mobility control algorithm improve the end-to-end capacity.

A Heuristic Control of Train Traffic in Disturbed Situations

A Heuristic Control of Train Traffic in Disturbed Situations

Design and control of agile automated CONWIP production lines

AbstractIn this article, we study the design and control of manufacturing cells with a mix of manual and automated equipment, operating under a CONWIP pull protocol, and staffed by a single agile (cross‐trained) worker. For a three‐station line with one automated station, we fully characterize the structure of the optimal control policy for the worker and show that it is a static priority policy. Using analytical models and extensive simulation experiments, we also evaluate the effectiveness of practical heuristic control policies and provide managerial insights on automation configuration design of the line. This characterization of the worker control policy enables us to develop managerial insights into the design issues of how best to locate and concentrate automation in the line. Finally, we show that, in addition to ease of control and greater design flexibility, the CONWIP protocol also offers higher efficiency and robustness than does the push protocol. © 2008 Wiley Periodicals, Inc. Naval Research Logistics 2009

D-OSKIL: A New Mechanism for Controlling Stick-Slip Oscillations in Oil Well Drillstrings

Limit cycles occurring in oil well drillstrings result from the interaction between the drill bit and the rock during drilling operations. In this paper, we propose to use the weight on the bit (WoB) force as an additional control variable to extinguish limit cycles when they occur. An approximate analysis based on the bias describing function and completed with some simulations, provides good evidence that the rotational dynamics of the oil well drillstring displays such a behavior. In particular, we propose an adaptation law for the WoB named D-OSKIL mechanisms, which results from a variant of the oscillation killer (OSKIL) mechanism studied in detail in [6]. In opposition to the heuristic control structure proposed in [7], we show that the new WoB (WoB) control law results in a globally asymptotically stable closed-loop system. Simulations applying the D-OSKIL mechanism show that the stick-slip oscillations can be eliminated without requiring a redesign of the velocity rotary table control.

The mechanics of biped running and a stable control strategy

This work presents an analysis of the mechanics of biped running with a heuristic control strategy for stable running. A tractable model of the mechanics is presented through principles, measures, and a time-distributed perspective. This model motivates the control strategy and provides a basis for extending the strategy to more general systems. The control strategy consists of a simple set of four rules, where the key rule considers the leg length upon liftoff. The Steady-State Index is proposed as a characterization of biped running. It identifies and relates the parameters affecting running and has broad applicability to both biological and robotic systems.

Naturally ventilated and mixed-mode buildings—Part II: Optimal control

Natural ventilation and a combination of natural ventilation and fan-assisted cooling, in lieu of or as a supplement to air conditioning, offer significant reductions in building energy use in appropriate climates. In current practice, such buildings are operated with heuristic control strategies, involving the opening of windows under suitable indoor and outdoor conditions. Such methods are sub-optimal because they do not account for building thermal dynamics and predicted weather and therefore do not make decisions on the basis of estimated future conditions. This paper uses building thermal predictions from a data-driven thermal model to assess the impact of window and internal openings and fan operation. It then develops a means of ranking and choosing among a set of cooling strategies, with the objective of maintaining occupied-period temperatures within a specified range and minimizing fan energy use. The control algorithms were assessed with data from a test building.

Design and analysis of partial protection mechanisms in groomed optical WDM mesh networks

We consider the problem of survivable network design in traffic-groomed optical WDM mesh networks that support subwavelength capacity connections. In typical survivable network designs, individual sessions are provided either full protection or no protection. We consider a quality of protection (QoP) framework where a connection is provided partial protection, i.e., when a link failure occurs on the primary path, the protection bandwidth provided on the backup path is less than or equal to the primary bandwidth. Each connection request specifies the primary bandwidth and a minimum backup bandwidth required. The network will guarantee at least the minimum backup bandwidth and, if capacity is available, higher backup bandwidth up to the primary path's bandwidth. The advantage of such a model is that it can reduce backup capacity requirements based on connection needs leading to lower blocking probability and lower network costs. We consider two scenarios: (i) a network with static traffic that is designed using an integer linear program (ILP) formulation and (ii) a network with dynamic traffic for which we present a heuristic connection admission control algorithm that prevents backup resource contention during recovery from a link failure. The results quantify the gain in blocking probability for different partial protection scenarios. The mechanism proposed to counter backup contention is seen to provide an average of 120% reduction in the contention among backup paths of connections traversing a link, especially when the number of wavelengths in each link is small.

Modeling and Simulation of a PEM Fuel Cell System for Aircraft Applications

A dynamic polymer electrolyte fuel cell system model including reformer, compressor, turbine and balance of pant models as wells as a heuristic control concept has been developed within MATLAB/Simulink. Within this paper emphasis is given to the model validation and dynamic system behavior. In addition the on-board water production and the system water balance were evaluated. The results point out an effective water gain if high effort for cooling is introduced and the load demand is higher than 65% of the nominal fuel cell stack power output. Moreover a response time of approximately 50s regarding load changes was derived from the simulation.

Transmission power and duration‐aware playout control for packetized media streaming over wireless links

AbstractWe investigate joint transmission power control and playout buffer control for packetized media streaming over wireless links. We propose a novel model formulation that tracks the play/freeze duration and play/freeze switch jitter to control the transmission power and playout rate (1 or 0, i.e., play or rebuffer). The model is especially appropriate for audio/music streaming. The optimal joint control is obtained using a Dynamic Programming approach to balance the average power used against achieved quality of service (QoS), reflecting play/freeze duration and jitter frequency. We also investigate two key special cases, where either only power control or rebuffer control is exercised; we obtain certain useful provable structural properties of these individual side controls. Based on those, we also design a low‐complexity heuristic control that ‘mimics’ the obtained structural properties of the optimal ones. Through simulation we see that the developed controls can achieve substantially higher performance over standard benchmark schemes. Copyright © 2008 John Wiley &amp; Sons, Ltd.

WIRELESS SENSOR NETWORK BASED CONTROL SYSTEM CONCIDERING COMMUNICATION COST

This paper is discussed on some new control methodologies for wireless sensor network based control system, minimizing communication energy consumption. Some control problems with communication cost saving are defined. Then, a heuristic control method based on the Model Predictive Control strategy with a receding horizon cost function including control performance and communication cost is proposed. For a state feedback control problem, a sufficient condition to keep stability of the closed loop system is obtained. Some numerical examples are also illustrated.

On performance characteristics for queueing systems with heterogeneous servers

The problem of optimal control for queueing system (QS) with heterogeneous servers was considering by many authors. In [8] it was shown that the optimal with respect to the number of jobs in the system minimization policy is a threshold type one and it obliges to use the fastest free server if necessary. However, calculation of performance characteristics under optimal policy and analysis of its preference before some other policies rest out of the investigators' interests. The purpose of this paper is to analyze a multi-server heterogeneous exponential queue. We demonstrate the methods for the calculation of the steady-state probabilities and deriving the waiting and sojourn time distributions. Some performance characteristics of such a system under the optimal control policy are calculated and compared with the same characteristics for the model under other heuristic control policies, e.g., the usage of the Fastest Free Server (FFS) or Random Server Selection (RSS).

An evaluation of new heuristics for the location of cross-docks distribution centers in supply chain network design

This paper addresses an evaluation of new heuristics solution procedures for the location of cross-docks and distribution centers in supply chain network design. The model is characterized by multiple product families, a central manufacturing plant site, multiple cross-docking and distribution center sites, and retail outlets which demand multiple units of several commodities. This paper describes two heuristics that generate globally feasible, near optimal distribution system design and utilization strategies utilizing the simulated annealing (SA) methodology. This study makes two important contributions. First, we continue the study of location planning for the cross-dock and distribution center supply chain network design problem. Second, we systematically evaluate the computational performance of this network design location model under more sophisticated heuristic control parameter settings to better understand interaction effects among the various factors comprising our experimental design, and present convergence results. The central idea of the paper is to evaluate the impact of geometric control mechanism vis-a-vis more sophisticated ones on solution time, quality, and convergence for two new heuristics. Our results suggest that integrating traditional simulated annealing with TABU search is recommended for this supply chain network design and location problem.

On the Matching and Proportional Laws of Cybernetic Models

The Matching and Proportional Laws are heuristic control policies that have found widespread use in cybernetic models of biological systems. Within this context, the laws serve as optimization surrogates for predicting the response of metabolic control circuits that modulate enzyme levels and activities. The key result of the current contribution is to demonstrate clearly the optimality properties of these laws and the assumptions that underlie their development. In doing so, we arrive at generalized versions of the Matching and Proportional Laws that are shown to collapse to the forms originally derived by Kompala et al. (Biotechnol. Bioeng. 1986, 28, 1044-1055) when certain simplifications are applied. As a further line of investigation, we show how Kompala et al.'s cybernetic laws compare with alternative control policies in their ability to describe diauxic growth behavior of microbial cultures. We find that Kompala et al.'s model describes the experimental observations more accurately than other limiting-case models that are either too aggressive or too passive in capturing the mixed-substrate growth rates and intermediate lag periods. Monte Carlo analysis of computational growth experiments in which strains obeying different regulatory policies directly compete for available nutrients reveals that the Matching and Proportional Law policy does not maximize the average growth rate of the culture. However, it allocates metabolic resources more frugally than other policies that outperform it and may be more realistic in reflecting the cell's true fitness-to-cost tradeoff as judged by its agreement with experimental growth data.

Determination of optimum operating conditions for industrial dye wastewater treatment using adaptive heuristic criticism pH control

For a pilot-scale application, pH control in the treatment of highly contaminated dye industrial wastewater containing metallic compounds as the main pollutants has been investigated with a method using adaptive heuristic criticism control (AHCC). Subsequent experimentation on between 12 and 18 l of the wastewater was carried out using statistical experimental design methodology to evaluate the effects of three critical factors: slaked lime (calcium hydroxide, Ca(OH) 2) concentration, iron chloride (FeCl 3) concentration and wastewater volume. With these critical factors, the wastewater treatment process is modeled as an appropriate quadratic cost function of the turbidity of the clarified water. The model is optimized with Rosenbrock's method. Response surface topology of the wastewater treatment is given in terms of optimal concentrations of lime water and FeCl 3 and optimal wastewater volume at pH 11.

Picklist generation algorithm with order-consolidation consideration for split-case module-based fulfilment centres

This paper serves as an initial study on order-consolidating time for a module-based order-picking system. In this system, items are stored in modules, and order picking is performed in waves that comprise more than one customer order. Picked items from multiple modules are conveyed to the packaging department for sortation based on customer orders. The order-consolidating time is the main focus as well as the performance measure in this paper. Order-consolidating time is the time difference between the arrival time of the first and the last item at the packaging department that belong to the same customer order. We proposed a heuristic control strategy, namely a pick-list generation algorithm, which will reduce the order-consolidating time. We named our proposed algorithm the push algorithm, which is an improvement algorithm. The push algorithm is compared with the basic algorithm to evaluate its performance. This comparison is extended under different environment settings to provide a robust conclusion. The experimental results indicate that the proposed algorithm consistently out-performs the basic algorithm in every tested environment with at least 17% improvement.

Multicommodity flow problems with a bounded number of paths: A flow deviation approach

AbstractWe propose a modified version of the Flow Deviation method of Fratta, Gerla, and Kleinrock to solve multicommodity problems with minimal congestion and a bounded number of active paths. We discuss the approximation of the min–max objective function by a separable convex potential function and give a mixed‐integer nonlinear model for the constrained routing problem. Heuristic control of the path generation is then embedded in the original algorithm based on the concepts of cleaning the quasi inactive paths and reducing the flow width for each commodity. Numerical experiments show the validity of the approach for realistic medium‐sized networks associated with routing problems in broadband communication networks with multiple protocols and label‐switched paths (MPLS). © 2006 Wiley Periodicals, Inc. NETWORKS, Vol. 49(1), 80–89 2007