Remarks on capture-avoidance games

We formulate the problems of capture and avoidance as differential games with terminal cost, thus avoiding some difficulties arising from choosing the terminal time or the closest distance as the cost. This puts capture and avoidance in the context of differential games, in the sense of Isaacs. The results are illustrated via linear differential games with hard control constraints.     

Motion detection and stochastic resonance in noisy environments

Several motion detection schemes are considered and their responses to noisy signals investigated. The schemes include the Reichardt correlation detector, shunting inhibition and the Horridge template model. These schemes are directionally selective and independent of the direction of change in contrast. They function by using spatial information and comparing it at successive time intervals. A rudimentary noise analysis is performed on the Reichardt and inhibition detectors to compare their natural robustness against noise. Using these detectors, stochastic resonance (SR) is applied, which is characterised by an improvement in response when noise is added to the input signal. It is found that the performance of the detectors degrades with the addition of noise. Employing Stocks' suprathreshold SR, an improvement can be gained when considering a network of detectors. Furthermore, when using an incorrect threshold setting for the template model, SR can be displayed.     

Collision avoidance for a mobile robot based on radial basis function hybrid force control technique

Collision avoidance is always difficult in the planning path for a mobile robot. In this paper, the virtual force field between a mobile robot and an obstacle is formed and regulated to maintain a desired distance by hybrid force control algorithm. Since uncertainties from robot dynamics and obstacle degrade the performance of a collision avoidance task, intelligent control is used to compensate for the uncertainties. A radial basis function (RBF) neural network is used to regulate the force field of an accurate distance between a robot and an obstacle in this paper and then simulation studies are conducted to confirm that the proposed algorithm is effective.     

Interference mitigation and avoidance in uplink OFDMA with collaborative distributed intracell scheduling

A distributed collaborative uplink scheduling model in OFDMA systems is extended to a multicell scenario. On the intercell level, the scenarios with and without base station cooperation are investigated. In the cooperative case, base stations collaborate by performing pricing-based power control based on exchanging interference information. In the absence of intercell collaboration, probabilistic transmission is applied in each cell for interference avoidance. Simulations show that the proposed intercell interference mitigation and avoidance schemes lead to enhanced results.     

ON AVOIDANCE ACTIVITIES IN FISHERY ENFORCEMENT MODELS

Compliance and enforcement in fisheries are important issues from an economic point of view since management measures are useless without a certain level of enforcement. These conclusions come from the well‐established theoretical literature on compliance and enforcement problems within fisheries and a common result is that, it is efficient to set fines as high as possible and monitoring as low as possible, when fines are costless and offenders are risk neutral. However, this result is sensitive to the assumption that fishermen cannot engage in avoidance activities, e.g., activities to reduce the likelihood of being detected when noncomplying. The paper presents a model of fisheries that allows the fishermen to engage in avoidance activities. The conclusions from the model are that, under certain circumstances, fines are costly transfers to society since they not only have a direct positive effect on the level of deterrence, but also an indirect negative effect in the form of increased avoidance activities to reduce the probability of detection. The paper contributes to the literature on avoidance activities by introducing the externality from the illegal behavior as an endogenous effect on other offenders. For an externality, that has an exogenous effect on other actors, Malik shows that fines are only costly transfers for conditional deterrence (when one actor is deterred while another actor is not). For fisheries, we show that fines are also costly transfers under no deterrence (when no agents are deterred).     

移动机器人超声波测距避障系统设计

测距避障是移动机器人适应未知复杂环境的能力之一,准确测出移动机器人和障碍物之间的距离是关键。以dsPIC33FJ256MC710单片机为核心研究设计了一种移动机器人超声波测距避障系统。该系统利用脉冲回波法测距,针对超声波在空气中的传播速度受环境温度的影响,设计了超声波速度温度补偿电路。实验结果表明该超声波测距避障系统测量数据准确,能够满足移动机器人在复杂环境中避障的需求。     

接近觉智能小车的设计开发

本文介绍了一种接近觉智能小车,该智能小车基于接近觉和STC89C52CR微处理器,采用模块化设计方案,结构简单,易于搭建平台和维修,测量精度高,可靠性好。该智能小车能够实现自动控制、被动控制、自动循迹、自动避障、测速、调速、速度显示、无线蓝牙通讯等功能,既能实现自动控制巡航,若用相关通信系统又可完成人工在线控制的功能。另外,对智能小车的超声波测距进行了温度补偿,有利于提高测距精度。接近觉智能小车的研制有助于研究以智能小车为模型的自动化驾驶技术,对智能车辆的研制与开发、现代化交通工具的智能化、多功能化发展提供了一个可行的参考方案。     

无人机自动防撞冲突检测与优化控制方法

研究了无人机防撞冲突检测与威胁级别评估方法, 建立了航向角控制、速度控制、高度控制以及航向角与速度组合控制等多种不同的防撞控制策略; 建立了自动防撞多目标代价函数模型以及多目标最优决策方法。仿真结果证明了该方法的有效性和较好的实用性。