In distributed computing by mobile robots, robots are deployed over a region, continuous or discrete, operating through a sequence of \textit{look-compute-move} cycles. An extensive study has been carried out to understand the computational powers of different robot models. The models vary on the ability to 1)~remember constant size information and 2)~communicate constant size message. Depending on the abilities the different models are 1)~$\mathcal{OBLOT}$ (robots are oblivious and silent), 2)~$\mathcal{FSTA}$ (robots have finite states but silent), 3)~$\mathcal{FCOM}$ (robots are oblivious but can communicate constant size information) and, 4)~$\mathcal{LUMI}$ (robots have finite states and can communicate constant size information). Another factor that affects computational ability is the scheduler that decides the activation time of the robots. The main three schedulers are \textit{fully-synchronous}, \textit{semi-synchronous} and \textit{asynchronous}. Combining the models ($M$) with schedulers ($K$), we have twelve combinations $M^K$. In the euclidean domain, the comparisons between these twelve variants have been done in different works for transparent robots, opaque robots, and robots with limited visibility. There is a vacant space for similar works when robots are operating on discrete regions like networks. It demands separate research attention because there have been a series of works where robots operate on different networks, and there is a fundamental difference when robots are operating on a continuous domain versus a discrete domain in terms of robots' movement. This work contributes to filling the space by giving a full comparison table for all models with two synchronous schedulers: fully-synchronous and semi-synchronous.
翻译:在移动机器人分布式计算中,机器人被部署于连续或离散区域,通过一系列“观察-计算-移动”周期进行操作。已有广泛研究致力于理解不同机器人模型的计算能力。这些模型在以下能力上存在差异:1) 记忆恒定规模信息的能力,2) 传递恒定规模信息的能力。根据能力差异,主要模型包括:1) $\mathcal{OBLOT}$(机器人无记忆且静默),2) $\mathcal{FSTA}$(机器人具有有限状态但静默),3) $\mathcal{FCOM}$(机器人无记忆但可传递恒定规模信息),4) $\mathcal{LUMI}$(机器人具有有限状态且可传递恒定规模信息)。影响计算能力的另一因素是决定机器人激活时序的调度器,主要分为完全同步、半同步和异步三种类型。将模型($M$)与调度器($K$)组合,可得到十二种组合 $M^K$。在欧几里得空间中,针对透明机器人、不透明机器人及有限可视范围机器人,已有不同研究对这十二种变体进行了比较分析。然而当机器人在网络等离散区域运行时,相关比较研究尚属空白。由于已有系列研究关注机器人在不同网络上的操作,且机器人在连续域与离散域中的运动方式存在本质差异,该领域需要独立的研究关注。本研究通过构建包含完全同步与半同步两种调度器的全模型对比表,填补了这一空白。