CN115843070B - Ocean sensing network calculation unloading method and system based on energy collection technology - Google Patents
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Abstract
Description
技术领域Technical Field
本发明涉及海洋观测传感网络技术领域,尤其涉及一种基于能量收集技术的海洋传感网络计算卸载方法及系统。The present invention relates to the technical field of ocean observation sensor networks, and in particular to an ocean sensor network computing offloading method and system based on energy harvesting technology.
背景技术Background Art
传统的海洋观测主要是以调查船、潜浮标为主的海基观测或以卫星遥感、航空观测为基础的天基观测。由于海洋环境的复杂性和独特性,海洋观测数据存在的短暂、不连续等问题一直制约着海洋科学的发展。源自冷战时期美国海军水声监视系统的海底观测网是人类建立的第三种海洋科学观测平台。在现代传感器、水下机器人、海底光纤电缆、物联网、大数据等新型技术的推动下,海底观测网融合物理海洋、海洋化学、海洋地球物理、海洋生态等学科,解决深海、极端环境下高分辨率和实时获取海洋观测数据的技术难题,可以深入到海洋内部观测和认识海洋,实现从海底到海面全天候、长期、连续、综合、实时、原位观测。Traditional ocean observations are mainly sea-based observations based on survey ships and submerged buoys or space-based observations based on satellite remote sensing and aerial observations. Due to the complexity and uniqueness of the marine environment, the short-term and discontinuous nature of marine observation data has always restricted the development of marine science. The seabed observation network, which originated from the US Navy's hydroacoustic surveillance system during the Cold War, is the third marine science observation platform established by humans. Driven by new technologies such as modern sensors, underwater robots, submarine fiber optic cables, the Internet of Things, and big data, the seabed observation network integrates disciplines such as physical oceanography, marine chemistry, marine geophysics, and marine ecology to solve the technical problems of high-resolution and real-time acquisition of marine observation data in deep sea and extreme environments. It can go deep into the ocean to observe and understand the ocean, and realize all-weather, long-term, continuous, comprehensive, real-time, and in-situ observations from the seabed to the sea surface.
建立分布式、网络化、互动式、综合性智能立体观测网是海洋科学观测的发展趋势。随着物联网技术在海洋领域的应用,通过统一、通用的数据标准整合分散在各处的观测站、观测节点、卫星遥感、无人水面艇等观测手段进行协同工作,形成覆盖近岸、区域及全球海域的层次化、综合化与智能化的空-天-海洋一体化立体观测网络。由于传感设备的资源(如计算和能源容量)有限,当能源较低时,计算能力会大幅下降,甚至会导致业务失败。通过传感网网关将传感设备中的计算任务卸载到远程云,可以有效解决计算问题。然而,云处理无法满足诸多观测应用的严格延迟要求,这些应用通常需要实时处理和响应(例如灾难响应)。Establishing a distributed, networked, interactive, comprehensive and intelligent three-dimensional observation network is the development trend of marine scientific observation. With the application of Internet of Things technology in the marine field, observation stations, observation nodes, satellite remote sensing, unmanned surface vessels and other observation methods scattered in various places are integrated through unified and universal data standards to work together to form a hierarchical, integrated and intelligent air-space-ocean integrated three-dimensional observation network covering nearshore, regional and global waters. Due to the limited resources (such as computing and energy capacity) of sensor equipment, when the energy is low, the computing power will drop significantly, and even cause business failure. Offloading the computing tasks in the sensor equipment to the remote cloud through the sensor network gateway can effectively solve the computing problem. However, cloud processing cannot meet the strict latency requirements of many observation applications, which usually require real-time processing and response (such as disaster response).
雾节点是雾体系结构的基本元素,雾节点可以是任何提供雾架构的计算、网络、存储和加速元素的设备,例如,工业控制器、交换机、路由器、嵌入式服务器、复杂网关、可编程逻辑控制器(PLC,ProgrammableLogic Controller)以及智能物联网节点(如视频监控摄像机)等。考虑到雾节点具有计算、存储网络资源的功能,因此,通过在海洋传感设备附近部署雾节点,可以有效提高海洋观测网的服务性能。Fog nodes are the basic elements of fog architecture. Fog nodes can be any device that provides computing, networking, storage, and acceleration elements of fog architecture, such as industrial controllers, switches, routers, embedded servers, complex gateways, programmable logic controllers (PLCs), and smart IoT nodes (such as video surveillance cameras). Considering that fog nodes have the functions of computing and storing network resources, the service performance of the ocean observation network can be effectively improved by deploying fog nodes near marine sensing equipment.
雾节点通常连接在传感网网关上,用于处理来自传感网设备的计算任务,以提供即时的业务响应;能量收集技术可以收集环境中容易获得的少量非传统能量并将之转化为电能,为传感设备持续供电。然而,在环境复杂、拓扑动态变化的海洋环境中,传统任务分配方式无法有效应用,由于服务质量(QoS,Quality of Service)的要求,传统卸载方法要么将所有计算任务卸载到最近的雾节点,这会导致一些雾节过载而传感设备负载不足;要么由传感设备承担计算任务,使得传感设备电量快速下降导致任务失败。因此,针对节点动态变化的海洋环境,现有的任务分配/卸载方法无法适用于应用了能量收集技术的海洋传感网络。Fog nodes are usually connected to sensor network gateways to process computing tasks from sensor network devices to provide immediate business responses; energy harvesting technology can collect small amounts of non-traditional energy that is easily available in the environment and convert it into electrical energy to continuously power sensor devices. However, in marine environments with complex environments and dynamically changing topologies, traditional task allocation methods cannot be effectively applied. Due to the requirements of Quality of Service (QoS), traditional offloading methods either offload all computing tasks to the nearest fog node, which will cause some fog nodes to be overloaded and sensor devices to be underloaded; or the sensor devices will take on the computing tasks, causing the battery power of the sensor devices to drop rapidly, resulting in task failure. Therefore, for marine environments with dynamically changing nodes, existing task allocation/offloading methods are not applicable to marine sensor networks that use energy harvesting technology.
发明内容Summary of the invention
为解决上述现有技术的不足,本发明提供了一种基于能量收集技术的海洋传感网络计算卸载方法及系统,适用于应用了能量收集技术的海洋传感网络,提供最优计算卸载策略,实现为海洋传感设备和雾节点确定合适的任务卸载比例,提高海洋传感网络的计算性能,避免节点资源浪费。In order to solve the deficiencies of the above-mentioned prior art, the present invention provides a method and system for offloading computing of an ocean sensor network based on energy harvesting technology, which is suitable for an ocean sensor network that uses energy harvesting technology, provides an optimal computing offloading strategy, and determines a suitable task offloading ratio for ocean sensor equipment and fog nodes, thereby improving the computing performance of the ocean sensor network and avoiding waste of node resources.
第一方面,本公开提供了一种基于能量收集技术的海洋传感网络计算卸载方法。In a first aspect, the present disclosure provides a method for offloading computation in an ocean sensor network based on energy harvesting technology.
一种基于能量收集技术的海洋传感网络计算卸载方法,包括:A method for offloading computation of an ocean sensor network based on energy harvesting technology, comprising:
在每一时隙内,获取当前时隙海洋传感设备的实时信息;所述实时信息包括海洋传感设备所请求计算任务的任务请求指示值、海洋传感设备访问雾节点的信道功率以及海洋传感设备的电池能量水平;In each time slot, real-time information of the ocean sensor device in the current time slot is obtained; the real-time information includes a task request indication value of the computing task requested by the ocean sensor device, a channel power for the ocean sensor device to access the fog node, and a battery energy level of the ocean sensor device;
构建海洋传感设备在当前时隙内执行计算任务的计算延迟和能量消耗,以及将计算任务卸载至雾节点的传输时延和能量消耗;Construct the computational delay and energy consumption of ocean sensor devices performing computational tasks in the current time slot, as well as the transmission delay and energy consumption of offloading computational tasks to fog nodes;
搭建计算任务执行成本模型、海洋传感设备能耗模型和能量收集模型,以长期平均执行成本最小为目标函数,结合所搭建的模型,构建计算卸载模型;Build a computing task execution cost model, a marine sensor equipment energy consumption model, and an energy collection model. Take the minimum long-term average execution cost as the objective function, and build a computing offloading model based on the built models.
根据所获取的实时信息,利用动态算法求解计算卸载模型,求解获得当前时隙的最优计算卸载决策。According to the real-time information obtained, the dynamic algorithm is used to solve the computation offloading model to obtain the optimal computation offloading decision for the current time slot.
进一步的技术方案,基于在第t个时隙时海洋传感设备完成计算任务所需的W个CPU周期的预定频率,构建海洋传感设备在第t个时隙内本地执行计算任务的计算延迟和能量消耗,公式为:A further technical solution is based on the predetermined frequency of W CPU cycles required for the ocean sensing device to complete the computing task at the tth time slot. , construct the computational delay of the ocean sensor device to perform the computational task locally in the tth time slot and energy consumption , the formula is:
其中,k为有效开关电容,w表示CPU周期个数,w=1,…,W。Where, k is the effective switching capacitance, w represents the number of CPU cycles, w=1,…,W.
进一步的技术方案,基于海洋传感设备访问雾节点的信道功率和发射功率,根据香农公式,构建海洋传感设备在第t个时隙内将计算任务卸载至雾节点的传输时延和能量消耗,公式为:A further technical solution is to access the channel power of fog nodes based on ocean sensing equipment and transmit power According to Shannon’s formula, the transmission delay of the ocean sensor device to offload the computing task to the fog node in the tth time slot is constructed. and energy consumption , the formula is:
其中,L表示计算任务的输入数据量,r表示第t个时隙的传输速率,且Where L represents the input data volume of the computing task, r represents the transmission rate of the tth time slot, and
上式中,ω表示信道带宽,σ表示信道内部的高斯噪声功率。In the above formula, ω represents the channel bandwidth, and σ represents the Gaussian noise power inside the channel.
进一步的技术方案,将执行延迟和任务丢弃成本的加权和作为计算任务执行成本,则计算任务执行成本模型为:A further technical solution is to use the weighted sum of execution delay and task abandonment cost as the calculation task execution cost, and then the calculation task execution cost model is:
其中,表示第t个时隙的计算任务执行成本,表示获取到计算任务后却未执行的惩罚,表示海洋传感设备在第t个时隙内本地执行计算任务的计算延迟,表示海洋传感设备在第t个时隙内将计算任务卸载至雾节点的传输时延,=1和=1分别表示在第t个时隙时,请求的计算任务在海洋传感设备上执行和计算任务卸载到雾节点。in, represents the execution cost of the computational task in the tth time slot, It indicates the penalty for not executing the computing task after obtaining it. represents the computational delay of the ocean sensor device in executing the computational task locally in the tth time slot, represents the transmission delay of the ocean sensor device offloading the computing task to the fog node in the tth time slot, =1 and =1 respectively indicates that at the tth time slot, the requested computing task is executed on the ocean sensor device and the computing task is offloaded to the fog node.
进一步的技术方案,在每个时隙中,将基于能量收集技术到达海洋传感设备的部分能量记为,构建能量收集模型,为:In a further technical solution, in each time slot, the part of the energy reaching the ocean sensing device based on the energy harvesting technology is recorded as , construct the energy harvesting model as:
其中,表示第t个时隙开始时到达海洋传感设备的能量。in, represents the energy reaching the ocean sensing device at the beginning of the tth time slot.
进一步的技术方案,所述海洋传感设备能耗模型为海洋传感设备在第t个时隙内所消耗的能量,公式为:In a further technical solution, the energy consumption model of the ocean sensing device is the energy consumed by the ocean sensing device in the tth time slot, and the formula is:
且满足能量关系约束:And satisfy the energy relationship constraints:
其中,表示第t个时隙时海洋传感设备的电池能量水平,表示计算卸载模型的指标,=1和=1分别表示在第t个时隙时,请求的计算任务在海洋传感设备上执行和计算任务卸载到雾节点,表示当前第t个时隙时CPU周期的预定频率,表示海洋传感设备访问雾节点的发射功率,表示海洋传感设备在第t个时隙内本地执行计算任务的能量消耗,表示海洋传感设备在第t个时隙内将计算任务卸载至雾节点的能量消耗。in, represents the battery energy level of the ocean sensing device at the tth time slot, Indicates the index for calculating the offloading model, =1 and =1 respectively indicates that at the tth time slot, the requested computing task is executed on the ocean sensor device and the computing task is offloaded to the fog node, Indicates the expected frequency of the CPU cycle at the current t-th time slot, represents the transmission power of the ocean sensor device accessing the fog node, represents the energy consumption of the ocean sensor device performing the computing task locally in the tth time slot, It represents the energy consumption of the ocean sensor device when offloading the computing task to the fog node in the tth time slot.
进一步的技术方案,所述计算卸载模型为:In a further technical solution, the calculation offloading model is:
s.t.s.t.
其中,表示第t个时隙时的最大传输功率,表示第t个时隙时最大CPU周期的预定频率,表示第t个时隙的计算任务执行成本,t=0,1,...,T-1,T表示时隙的总个数,表示当前第t个时隙时海洋传感设备的电池能量水平,表示计算卸载模型的指标,=1和=1分别表示在第t个时隙时,请求的计算任务在海洋传感设备上执行和计算任务卸载到雾节点,表示当前第t个时隙时CPU周期的预定频率,表示海洋传感设备访问雾节点的发射功率,表示到达海洋传感设备的部分能量,表示第t个时隙时海洋传感设备完成计算任务所需的W个CPU周期的预定频率。in, represents the maximum transmission power at the tth time slot, represents the predetermined frequency of the maximum CPU cycle at the tth time slot, represents the execution cost of the computational task in the tth time slot, t=0,1,...,T-1, T represents the total number of time slots, represents the battery energy level of the ocean sensor device at the current t-th time slot, Indicates the index for calculating the offloading model, =1 and =1 respectively indicates that at the tth time slot, the requested computing task is executed on the ocean sensor device and the computing task is offloaded to the fog node, Indicates the expected frequency of the CPU cycle at the current t-th time slot, represents the transmission power of the ocean sensor device accessing the fog node, represents the portion of energy reaching the ocean sensing device, Represents the predetermined frequency of W CPU cycles required for the ocean sensor device to complete the computing task at the tth time slot.
进一步的技术方案,利用动态算法求解当前时隙内的最优计算卸载决策,包括:A further technical solution uses a dynamic algorithm to solve the optimal computing offloading decision in the current time slot, including:
构建李雅普诺夫函数;Construct Lyapunov functions;
根据李雅普诺夫函数,构建李雅普诺夫漂移函数和李雅普诺夫漂移加惩罚函数;According to the Lyapunov function, construct the Lyapunov drift function and the Lyapunov drift plus penalty function;
根据李雅普诺夫漂移函数和李雅普诺夫漂移加惩罚函数,化简计算卸载模型;According to the Lyapunov drift function and the Lyapunov drift plus penalty function, the unloading model is simplified and calculated;
对化简后的计算卸载模型进行求解,得到当前时隙内的最优计算卸载决策。The simplified computation offloading model is solved to obtain the optimal computation offloading decision in the current time slot.
进一步的技术方案,所述求解包括:A further technical solution is that the solution includes:
在第t个时隙开始时,获取当前时隙海洋传感设备所请求计算任务的任务请求指示值、海洋传感设备的电池能量水平和海洋传感设备访问雾节点的信道功率;At the beginning of the tth time slot, obtain the task request indication value of the computing task requested by the ocean sensing device in the current time slot , Battery energy levels of ocean sensing devices and channel power for ocean sensor devices to access fog nodes ;
根据所获取的当前时隙的信息,代入化简后的计算卸载模型中进行求解,确定当前时隙的计算卸载模型的指标、CPU周期的预定频率、海洋传感设备访问雾节点的发射功率基于能量收集技术到达海洋传感设备的部分能量;According to the information of the current time slot obtained, substitute it into the simplified calculation offloading model for solution to determine the index of the calculation offloading model of the current time slot , the predetermined frequency of CPU cycles , Transmission power of marine sensor equipment accessing fog nodes Part of the energy reaching ocean sensing devices based on energy harvesting technology ;
根据计算确定的结果更新海洋传感设备的电池能量队列,并判断是否达到当前时隙的稳定值,若稳定,则将计算确定的结果作为当前时隙内的最优计算卸载决策输出,否则计算下一时隙的最优计算卸载决策。The battery energy queue of the ocean sensor equipment is updated according to the calculated results, and it is determined whether the stable value of the current time slot is reached. If stable, the calculated results are output as the optimal computing unloading decision in the current time slot, otherwise the optimal computing unloading decision for the next time slot is calculated.
第二方面,本公开提供了一种基于能量收集技术的海洋传感网络计算卸载系统。In a second aspect, the present disclosure provides a marine sensor network computing offloading system based on energy harvesting technology.
一种基于能量收集技术的海洋传感网络计算卸载系统,包括:A marine sensor network computing unloading system based on energy harvesting technology, comprising:
信息获取模块,用于在每一时隙内,获取当前时隙海洋传感设备的实时信息,所述实时信息包括海洋传感设备所请求计算任务的任务请求指示值、海洋传感设备访问雾节点的信道功率以及海洋传感设备的电池能量水平;An information acquisition module is used to acquire real-time information of the ocean sensor device in the current time slot in each time slot, wherein the real-time information includes a task request indication value of the computing task requested by the ocean sensor device, a channel power for the ocean sensor device to access the fog node, and a battery energy level of the ocean sensor device;
模型构建模块,用于构建海洋传感设备在当前时隙内执行计算任务的计算延迟和能量消耗,以及将计算任务卸载至雾节点的传输时延和能量消耗,搭建计算任务执行成本模型、海洋传感设备能耗模型和能量收集模型,以长期平均执行成本最小为目标函数,结合所搭建的模型,构建计算卸载模型;The model building module is used to construct the computational delay and energy consumption of the ocean sensor equipment in executing the computational task in the current time slot, as well as the transmission delay and energy consumption of offloading the computational task to the fog node, build the computational task execution cost model, the ocean sensor equipment energy consumption model and the energy collection model, and build the computational offloading model with the minimum long-term average execution cost as the objective function in combination with the built model;
卸载决策求解模块,用于根据所获取的实时信息,利用动态算法求解计算卸载模型,求解获得当前时隙的最优计算卸载决策。The offloading decision solving module is used to solve the computing offloading model using a dynamic algorithm based on the acquired real-time information, and to obtain the optimal computing offloading decision for the current time slot.
以上一个或多个技术方案存在以下有益效果:One or more of the above technical solutions have the following beneficial effects:
1、本发明提供了一种基于能量收集技术的海洋传感网络计算卸载方法及系统,通过获取海洋传感设备在每一时隙内的实时信息,构建海洋传感设备在该时隙内执行计算任务的计算延迟和能量消耗以及将计算任务卸载至雾节点的传输时延和能量消耗,以此建立计算任务执行成本模型、海洋传感设备能耗模型和能量收集模型,并综合所构建的模型,以长期平均执行成本最小为目标函数,构建计算卸载模型,利用动态算法求解当前时隙内的最优计算卸载决策,实现了为应用能量收集技术的海洋传感网络提供最优计算卸载策略,为海洋传感设备和雾节点确定合适的任务卸载比例,提高海洋传感网络的计算性能,避免了节点资源浪费。1. The present invention provides a method and system for computing offloading of an ocean sensor network based on energy harvesting technology. By acquiring real-time information of an ocean sensor device in each time slot, the computing delay and energy consumption of the ocean sensor device in executing computing tasks in the time slot, as well as the transmission delay and energy consumption of offloading computing tasks to fog nodes are constructed, thereby establishing a computing task execution cost model, an ocean sensor device energy consumption model, and an energy harvesting model. The constructed models are integrated to construct a computing offloading model with the minimum long-term average execution cost as the objective function. A dynamic algorithm is used to solve the optimal computing offloading decision in the current time slot, thereby providing an optimal computing offloading strategy for an ocean sensor network that uses energy harvesting technology, determining a suitable task offloading ratio for ocean sensor devices and fog nodes, improving the computing performance of the ocean sensor network, and avoiding waste of node resources.
2、本发明考虑了海洋传感设备资源有限,无法满足存储最优策略内存需求的问题,提出了一种动态算法进行求解,利用李雅普诺夫漂移函数和李雅普诺夫漂移加惩罚函数化简计算卸载模型,根据获取的实时信息进行迭代求解,获取当前最优计算卸载决策,以此进行资源分配,优化资源分配结果,减少长期平均执行成本,提高系统的用户服务质量。2. The present invention takes into account the problem that the resources of marine sensor equipment are limited and cannot meet the memory requirements for storing the optimal strategy, and proposes a dynamic algorithm for solving it. It uses the Lyapunov drift function and the Lyapunov drift plus penalty function to simplify the calculation offloading model, and iterates the solution based on the real-time information obtained to obtain the current optimal calculation offloading decision, so as to allocate resources, optimize the resource allocation results, reduce the long-term average execution cost, and improve the user service quality of the system.
附图说明BRIEF DESCRIPTION OF THE DRAWINGS
构成本发明的一部分的说明书附图用来提供对本发明的进一步理解,本发明的示意性实施例及其说明用于解释本发明,并不构成对本发明的不当限定。The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.
图1为本发明实施例所述基于能量收集技术的海洋传感网络计算卸载方法的流程图;FIG1 is a flow chart of a method for offloading computation in an ocean sensor network based on energy harvesting technology according to an embodiment of the present invention;
图2为本发明实施例中计算卸载模型的示意图;FIG2 is a schematic diagram of a computational offloading model in an embodiment of the present invention;
图3为本发明实施例中能量收集的示意图。FIG. 3 is a schematic diagram of energy collection in an embodiment of the present invention.
具体实施方式DETAILED DESCRIPTION
应该指出,以下详细说明都是示例性的,旨在对本发明提供进一步的说明。除非另有指明,本文使用的所有技术和科学术语具有与本发明所属技术领域的普通技术人员通常理解的相同含义。It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.
需要注意的是,这里所使用的术语仅是为了描述具体实施方式,而非意图限制根据本发明的示例性实施方式。如在这里所使用的,除非上下文另外明确指出,否则单数形式也意图包括复数形式,此外,还应当理解的是,当在本说明书中使用术语“包含”和/或“包括”时,其指明存在特征、步骤、操作、器件、组件和/或它们的组合。It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and/or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and/or combinations thereof.
实施例一Embodiment 1
本实施例提供了一种基于能量收集技术的海洋传感网络计算卸载方法,如图1所示,包括:This embodiment provides a method for offloading computation in an ocean sensor network based on energy harvesting technology, as shown in FIG1 , including:
步骤S1、在每一时隙内,获取当前时隙海洋传感设备的实时信息,所述实时信息包括海洋传感设备所请求计算任务的任务请求指示值、海洋传感设备访问雾节点的信道功率以及海洋传感设备的电池能量水平;Step S1, in each time slot, obtaining the real-time information of the ocean sensor device in the current time slot, wherein the real-time information includes the task request indication value of the computing task requested by the ocean sensor device, the channel power of the ocean sensor device accessing the fog node, and the battery energy level of the ocean sensor device;
步骤S2、构建海洋传感设备在当前时隙内执行计算任务的计算延迟和能量消耗,以及将计算任务卸载至雾节点的传输时延和能量消耗;Step S2: construct the computational delay and energy consumption of the ocean sensor device executing the computational task in the current time slot, as well as the transmission delay and energy consumption of offloading the computational task to the fog node;
步骤S3、搭建计算任务执行成本模型、海洋传感设备能耗模型和能量收集模型,以长期平均执行成本最小为目标函数,结合所搭建的模型,构建计算卸载模型;Step S3: construct a computing task execution cost model, a marine sensor equipment energy consumption model, and an energy collection model, and construct a computing offloading model by taking the minimum long-term average execution cost as the objective function and combining the constructed models;
步骤S4、根据所获取的实时信息,利用动态算法求解计算卸载模型,求解获得当前时隙的最优计算卸载决策,其中,该计算卸载决策用以表征海洋传感设备所请求的计算任务的执行方式。Step S4: according to the acquired real-time information, a dynamic algorithm is used to solve the computational offloading model to obtain the optimal computational offloading decision for the current time slot, wherein the computational offloading decision is used to characterize the execution mode of the computational task requested by the ocean sensing device.
本实施例考虑数个拥有计算能力的海洋传感设备和雾节点组成的计算卸载模型,如图2所示,雾节点位于距离海洋传感设备d米处,并与海洋观测网通信连接,该海洋传感设备(如图2所示的海洋传感设备A、B、C)可以是船舶、海岸基站等,可以通过无线信道对雾节点访问。海洋传感设备关联该节点服务器并运行一个虚拟机,执行代表传感设备的计算任务,且通过将部分计算任务转移到该节点执行,可以显著提升服务质量QoS。This embodiment considers a computing offloading model consisting of several ocean sensor devices with computing capabilities and fog nodes. As shown in Figure 2, the fog node is located d meters away from the ocean sensor device and is connected to the ocean observation network. The ocean sensor device (ocean sensor devices A, B, C shown in Figure 2) can be a ship, a coastal base station, etc., and the fog node can be accessed through a wireless channel. The ocean sensor device is associated with the node server and runs a virtual machine to perform computing tasks on behalf of the sensor device, and by transferring part of the computing tasks to the node for execution, the service quality QoS can be significantly improved.
上述步骤S1中,获取海洋传感设备在当前时隙的实时信息。该实时信息包括海洋传感设备所请求计算任务的任务请求指示值、海洋传感设备访问雾节点的信道功率以及海洋传感设备的电池能量水平。根据所获取的信息,求解所构建的计算卸载模型,求解获得每一时隙内的最优计算卸载决策。In the above step S1, the real-time information of the ocean sensing device in the current time slot is obtained. The real-time information includes the task request indication value of the computing task requested by the ocean sensing device. , Channel power of ocean sensor devices accessing fog nodes and battery energy levels of ocean sensing devices According to the acquired information, the constructed computation offloading model is solved to obtain the optimal computation offloading decision in each time slot.
在本实施例中,将时间切片为多个时隙(或时间片),每个时隙的长度为,标号为Γ∈{0,1,...},无线信道在每个时隙内保持静态,但在不同时隙之间变化。用A(L,)表示一个计算任务,其中,L(单位是位,bit)表示该计算任务的数据量大小,而表示计算任务完成的截至时间,即计算任务A(L,)需要在时间内完成。海洋传感设备上运行应用程序,该程序所请求的计算任务被建模为一个伯努利进程。在每个时隙开始时,计算任务A(L,)有ρ的概率被请求,相应的,则有(1-ρ)的概率未被请求。若计算任务在第t个时隙内被请求时,令任务请求指示值= 1,否则= 0,也即P(=1)=1-P(=0)=ρ,t∈Γ,P(=1)=ρ表示计算任务被请求时的概率为ρ,P(=0)=1-ρ表示计算任务未被请求时的概率为1-ρ。本实施例中,没有缓冲区可用于计算请求排队,且海洋传感设备上运行的应用程序为关注任务执行时间不大于时隙长度的延迟敏感型应用,即。In this embodiment, the time is sliced into multiple time slots (or time slices), and the length of each time slot is , labeled Γ∈{0,1,...}, the wireless channel remains static within each time slot, but changes between different time slots. ) represents a computing task, where L (in bits) represents the data size of the computing task, and Indicates the deadline for the completion of the computing task, that is, the computing task A(L, ) Need to be in time The application is run on the ocean sensor device, and the computing task requested by the program is modeled as a Bernoulli process. At the beginning of each time slot, the computing task A(L, ) is requested with probability ρ, and accordingly, it is not requested with probability (1-ρ). If the computing task is requested in the tth time slot, let the task request indicator value = 1, otherwise = 0, that is, P( =1)=1-P( =0)=ρ,t∈Γ,P( =1)=ρ means the probability of computing task being requested is ρ, P( =0)=1-ρ means that the probability that the computing task is not requested is 1-ρ. In this embodiment, there is no buffer available for queuing computing requests, and the application running on the ocean sensing device is a delay-sensitive application that focuses on the task execution time not being greater than the time slot length, that is, .
获取第t个时隙时海洋传感设备访问雾节点的信道功率,其中,∽(x)且t∈ Γ,(x)是的累积分布函数(CDF,cumulativedistribution function)。Get the channel power of the ocean sensor device accessing the fog node at the tth time slot ,in, ∽ (x) and t∈ Γ, (x) Yes The cumulative distribution function (CDF) of .
在获取上述海洋传感设备的实时信息后,执行步骤S2,根据获取的海洋传感设备的实时信息,构建海洋传感设备在该时隙内执行计算任务的计算延迟和能量消耗,以及海洋传感设备在该时隙内将计算任务卸载至雾节点的传输时延和能量消耗。After acquiring the real-time information of the above-mentioned ocean sensor device, execute step S2, and construct the computational delay and energy consumption of the ocean sensor device performing the computational task within the time slot according to the acquired real-time information of the ocean sensor device, as well as the transmission delay and energy consumption of the ocean sensor device offloading the computational task to the fog node within the time slot.
具体的,每个计算任务可以在海洋传感设备上本地执行,也可以卸载到雾节点上由其执行。令∈{0,1},j={m,s},将作为计算卸载模型的指标,其中,=1和=1则分别表示在第t个时隙时,请求的计算任务在海洋传感设备上执行或卸载到雾节点,具体的,当=1时,则有=0,表示在第t个时隙时,请求的计算任务在海洋传感设备上执行;当=1时,则有=0,表示在第t个时隙时,请求的计算任务卸载到雾节点上执行。因此,计算卸载模型应满足:Specifically, each computing task can be executed locally on the ocean sensor device or offloaded to the fog node for execution. ∈{0,1}, j={m,s}, As an indicator for calculating the unloading model, =1 and =1 respectively indicates that at the tth time slot, the requested computing task is executed on the ocean sensor device or offloaded to the fog node. Specifically, when =1, then =0, indicating that at the tth time slot, the requested computing task is executed on the ocean sensor device; =1, then =0, indicating that at the tth time slot, the requested computing task is offloaded to the fog node for execution. Therefore, the computing offloading model should satisfy:
+=1,t ∈ Γ + =1, t∈Γ
海洋传感设备完成该计算任务需要多个CPU周期的预定频率。将处理1bit大小输入数据所需的CPU周期数记为X,该值可用离线测量的方法根据不同的应用获得,而完成计算任务A(L,),则需要W = LX个CPU周期。在第t个时隙内完成计算任务需要W个CPU周期,将该第t个时隙时W个CPU周期的预定频率记为,即一个时隙对应一个预定频率,该频率可通过DVFS技术调节芯片电压实现。The ocean sensing device needs a predetermined frequency of multiple CPU cycles to complete the computing task. The number of CPU cycles required to process 1 bit of input data is recorded as X, which can be obtained by offline measurement according to different applications, and the number of CPU cycles required to complete the computing task A(L, ), then W = LX CPU cycles are required. It takes W CPU cycles to complete the computing task in the tth time slot, and the predetermined frequency of W CPU cycles in the tth time slot is recorded as , that is, one time slot corresponds to a predetermined frequency, which can be achieved by adjusting the chip voltage through DVFS technology.
基于在第t个时隙时海洋传感设备完成计算任务所需的W个CPU周期的预定频率,构建海洋传感设备在t时刻执行计算任务的计算延迟,为:Based on the predetermined frequency of W CPU cycles required for the ocean sensor device to complete the computing task at the tth time slot , construct the computational delay of the ocean sensor device performing the computational task at time t ,for:
相应地,构建海洋传感设备在t时刻本地执行计算任务的能量消耗,为:Accordingly, the energy consumption of constructing ocean sensing equipment to perform computing tasks locally at time t is ,for:
其中,k为有效开关电容,其取值取决于芯片架构。Where k is the effective switch capacitance, and its value depends on the chip architecture.
为了减少移动执行时的计算量,将计算任务A(L,)卸载到雾节点。在本实施例中,假设计算任务的输入数据量较小,因此反馈的传输延迟也可以忽略。基于海洋传感设备访问雾节点的信道功率和发射功率,根据香农公式,构建海洋传感设备在第t个时隙内将计算任务卸载至雾节点的传输时延,为:In order to reduce the amount of calculation during the move execution, the calculation task A(L, ) is unloaded to the fog node. In this embodiment, it is assumed that the input data volume of the computing task is small, so the transmission delay of the feedback can also be ignored. Channel power of ocean sensing equipment accessing fog nodes and transmit power According to Shannon’s formula, the transmission delay of the ocean sensor device to offload the computing task to the fog node in the tth time slot is constructed. ,for:
其中,L表示计算任务的输入数据量,r表示第t个时隙的传输速率,且:Where L represents the input data volume of the computing task, r represents the transmission rate of the tth time slot, and:
上式中,ω表示信道带宽,σ表示信道内部的高斯噪声功率。In the above formula, ω represents the channel bandwidth, and σ represents the Gaussian noise power inside the channel.
相应地,构建海洋传感设备在第t个时隙内将计算任务卸载至雾节点的能量消耗,为:Accordingly, the energy consumption of constructing the ocean sensor device to offload the computing task to the fog node in the tth time slot is ,for:
。 .
上述步骤S3中,在通过步骤S2获取海洋传感设备在不同情况下执行计算任务的时延和能耗的基础上,首先构建计算任务执行成本模型、海洋传感设备能耗模型和能量收集模型。In the above step S3, based on the delay and energy consumption of the ocean sensor equipment in performing computing tasks under different circumstances obtained in step S2, a computing task execution cost model, an ocean sensor equipment energy consumption model and an energy collection model are first constructed.
在应用能量收集技术的设备中,计算卸载策略的设计比传统的移动云计算系统更加复杂,电池能量水平与时间相关,使得系统决策在不同时隙耦合。因此,最优的计算卸载策略应该在当前计算任务和未来计算任务的计算性能之间取得良好的平衡。In devices that apply energy harvesting technology, the design of computation offloading strategies is more complicated than in traditional mobile cloud computing systems. Battery energy levels are time-dependent, making system decisions coupled at different time slots. Therefore, the optimal computation offloading strategy should achieve a good balance between the computational performance of current and future computational tasks.
任务执行延迟是用户QoS(Quality ofService,服务质量)的关键指标之一,本实施例用QoS来计算卸载策略。由于收集到的能量具有间歇性和散发性,一些请求的计算任务可能无法执行而不得不放弃,例如由于本地计算能量不足,而从海洋传感设备到雾节点的无线通道处于深度衰落,即任务无法卸载。考虑到这一点,对每个被放弃的计算任务按一个成本单位进行惩罚。因此,本实施例构建计算任务执行成本模型,将该执行成本定义为执行延迟和任务丢弃成本的加权和,可以用下式表示:Task execution delay is one of the key indicators of user QoS (Quality of Service). This embodiment uses QoS to calculate the unloading strategy. Since the collected energy is intermittent and scattered, some requested computing tasks may not be executed and have to be abandoned. For example, due to insufficient local computing energy, the wireless channel from the ocean sensor device to the fog node is in deep fading, that is, the task cannot be unloaded. Taking this into account, each abandoned computing task is penalized at a cost unit. Therefore, this embodiment constructs a computing task execution cost model, and defines the execution cost as the weighted sum of the execution delay and the task abandonment cost, which can be expressed as the following formula:
其中,表示获取到计算任务后却未执行的惩罚,实际上,该惩罚也属于任务执行成本。in, It indicates the penalty for not executing the computing task after obtaining it. In fact, this penalty is also part of the task execution cost.
如图3所示,能量收集过程可以认为是连续的能量包到达海洋传感设备中,具体的,通过换能器和转换电路将风能、潮汐能、太阳能转换为电能,电能直接或通过电源管理电路间接存储到能量存储设备(如本实施例所述的海洋传感设备)中。通过能量收集,在第t个时隙开始时到达海洋传感设备的能量,其中,不同时隙的的最大值为。在每个时隙中,将基于能量收集技术到达海洋传感设备的部分能量记为,构建能量收集模型,为:As shown in FIG3 , the energy collection process can be considered as continuous energy packets arriving at the ocean sensor device. Specifically, wind energy, tidal energy, and solar energy are converted into electrical energy through transducers and conversion circuits, and the electrical energy is directly or indirectly stored in the energy storage device (such as the ocean sensor device described in this embodiment) through power management circuits. Through energy collection, the energy arriving at the ocean sensor device at the beginning of the tth time slot , where different time slots The maximum value of In each time slot, the portion of energy reaching the ocean sensing device based on energy harvesting technology is recorded as , construct the energy harvesting model as:
其中,,为所有时隙中到达能量的最大值。in, , is the maximum value of the energy arriving in all time slots.
上述能量被收集并存储在海洋传感设备的电池中,在下一时隙中,可以用于本地计算或进行计算卸载。The above energy is collected and stored in the battery of the ocean sensing device, and can be used for local computing or computation offloading in the next time slot.
进而,构建海洋传感设备能耗模型,即海洋传感设备在第t个时隙内所消耗的能量,为:Then, the energy consumption model of the ocean sensing equipment is constructed, that is, the energy consumed by the ocean sensing equipment in the tth time slot is:
同时满足以下能量关系约束:At the same time, the following energy relationship constraints are met:
其中,B表示海洋传感设备的电池能量水平,表示第t个时隙(即当前时隙)海洋传感设备的电池能量水平。Where, B represents the battery energy level of the ocean sensing device, Represents the battery energy level of the ocean sensing device at the tth time slot (i.e., the current time slot).
由此,海洋传感设备电池的能量水平变化可以描述为:Therefore, the energy level change of the battery of the ocean sensing device can be described as:
。 .
然后,以长期平均执行成本最小为目标函数,结合所搭建的模型,构建计算卸载模型。Then, taking the minimization of the long-term average execution cost as the objective function and combining the constructed model, a computational offloading model is constructed.
具体的,将优化问题描述为以长期平均执行成本最小为目标函数,构建计算卸载模型,为:Specifically, the optimization problem It is described as taking the minimization of the long-term average execution cost as the objective function to build a computation offloading model, which is:
s.t.s.t.
上式中,表示第t个时隙时的最大传输功率(即最大发射功率),表示第t个时隙时的最大CPU预定频率,T表示时隙的总个数,t=0,1,...,T-1。In the above formula, represents the maximum transmission power (i.e., maximum transmit power) at the tth time slot, It represents the maximum CPU scheduled frequency in the tth time slot, T represents the total number of time slots, t=0,1,...,T-1.
在构建完成计算卸载模型后,执行步骤S4,即根据所获取的实时信息,利用动态算法求解计算卸载模型,求解获得当前时隙的最优计算卸载决策。After the computation offloading model is constructed, step S4 is executed, that is, according to the acquired real-time information, the computation offloading model is solved by using a dynamic algorithm to obtain the optimal computation offloading decision for the current time slot.
在所考虑的卸载系统中,系统状态由任务请求、可收集能量、电池能量水平和信道状态组成,动作为能量收集和计算卸载决策,包括CPU周期调度频率和分配的发射功率。操作仅依赖于当前系统状态。此外,由于是以长期平均执行成本最小为目标函数,因此,问题实际上是一个马尔科夫决策过程(MDP,MarkovDecision Process)问题。原则上,问题可以通过标准的MDP算法得到最优解,如相对值迭代算法和线性规划重公式方法。然而,这两种算法均需要使用有限状态来描述系统,并离散可行行动集。由于MDP算法是基于数值迭代的,因此很难获得解决方案。此外,量化状态和可行动作集可能会导致严重的性能退化,海洋传感设备资源十分有限,无法满足存储最优策略的内存需求。因此,本实施例提出一个动态求解算法来解决问题。In the offloading system considered, the system state consists of task requests, harvestable energy, battery energy level, and channel status, and the actions are energy harvesting and computation offloading decisions, including CPU cycle scheduling frequency and allocated transmit power. The operation depends only on the current system state. In addition, since the objective function is to minimize the long-term average execution cost, the problem It is actually a Markov decision process (MDP) problem. In principle, the problem The optimal solution can be obtained through standard MDP algorithms, such as the relative value iteration algorithm and the linear programming reformulation method. However, both algorithms require the use of finite states to describe the system and discretize the feasible action set. Since the MDP algorithm is based on numerical iteration, it is difficult to obtain a solution. In addition, quantizing the state and the feasible action set may cause serious performance degradation. The resources of marine sensor equipment are very limited and cannot meet the memory requirements for storing the optimal strategy. Therefore, this embodiment proposes a dynamic solution algorithm to solve the problem .
计算卸载决策(即计算卸载模型的解)在某一个时间节点可以用一个多维向量描述,李雅普诺夫函数(Lyapunov函数)则是对这个多为向量所表示的状态的非负、标量的表述。若系统朝向不被期望的方向发展,那么Lyapunov函数就会变大,因此,将Lyapunov函数沿着x轴的负方向逼近到0,使之趋于稳定,当达到Lyapunov稳定后,则认为此时的计算卸载决策(即由多维向量构成的解)为当前时间节点的最优决策。The computational offloading decision (i.e., the solution of the computational offloading model) can be described by a multidimensional vector at a certain time node, and the Lyapunov function is a non-negative, scalar representation of the state represented by this multidimensional vector. If the system develops in an undesirable direction, the Lyapunov function will become larger. Therefore, the Lyapunov function is approached to 0 along the negative direction of the x-axis to make it stable. When Lyapunov stability is reached, the computational offloading decision (i.e., the solution composed of multidimensional vectors) at this time is considered to be the optimal decision at the current time node.
在本实施例中,首先,基于当前时隙的海洋传感设备的电池能量水平,构建李雅普诺夫函数,具体如下式所示:In this embodiment, firstly, based on the battery energy level of the ocean sensing device in the current time slot, a Lyapunov function is constructed, as shown in the following formula:
然后,构建李雅普诺夫漂移函数,具体如下式所示:Then, construct the Lyapunov drift function, as shown in the following formula:
在李雅普诺夫漂移函数中引入期望,引入的期望如下式所示:Introducing expectation into the Lyapunov drift function, the introduced expectation is shown as follows:
上式中,表示取期望。In the above formula, Indicates expectation.
自然地,Naturally,
其中,C是大于0的有上界的常数。Where C is a constant with an upper bound greater than 0.
由于求解问题(即计算卸载模型的目标函数)获得最优解,其计算复杂、难以计算,因此通过上述方式适当放大形成问题,通过求解问题得到问题的最优解集。所形成的问题为:Because of the problem (i.e., calculating the objective function of the unloading model) to obtain the optimal solution, the calculation is complex and difficult to calculate, so the above method is appropriately enlarged to form a problem , by solving the problem Get the question The optimal solution set of . The problem formed for:
s.t.s.t.
在问题的基础上再次化简,即对所有时隙的李雅普诺夫漂移函数进行累加,得:In question Based on this, we can simplify it again, that is, accumulate the Lyapunov drift functions of all time slots, and get:
上式中,表示第0个时隙时海洋传感设备的电池能量水平,即海洋传感设备的初始电池能量水平,通常设=0;表示在经过T个时隙(指0~T-1共T个时隙)后,第T个时隙时海洋传感设备的电池能量水平。In the above formula, It represents the battery energy level of the ocean sensor device at the 0th time slot, that is, the initial battery energy level of the ocean sensor device. =0; It indicates the battery energy level of the ocean sensor device at the Tth time slot after T time slots (a total of T time slots from 0 to T-1).
对上述等式两边取期望,得:Taking the expectation on both sides of the above equation, we get:
为了使上式成立,令,则可得到问题,为:In order to make the above equation valid, let , then we can get the problem ,for:
s.t.s.t.
因此,李雅普诺夫漂移函数和李雅普诺夫漂移加惩罚函数可以表示为:Therefore, the Lyapunov drift function and the Lyapunov drift plus penalty function can be expressed as:
在每个时隙内求其最小值,借助权重V来调节对和的重视程度,因此形成新的问题,即:Find the minimum value in each time slot and adjust the and The level of attention paid to this issue has led to new problems ,Right now:
s.t.s.t.
通过上述方案,利用李雅普诺夫漂移函数和李雅普诺夫漂移加惩罚函数,化简计算卸载模型,将难以求解最优解的问题转换值问题,通过求解问题获取与最优解相差无几且包含最优解的解集。Through the above scheme, using Lyapunov drift function and Lyapunov drift plus penalty function, the calculation of unloading model is simplified, and the problem of finding the optimal solution is difficult to solve. Conversion value problem , by solving the problem Get a set of solutions that are close to the optimal solution and include the optimal solution.
在完成计算卸载模型的化简后,通过下述算法求解问题的渐进最优解,即求解当前时隙内的最优计算卸载决策。After completing the simplification of the computational unloading model, the problem is solved by the following algorithm: The asymptotically optimal solution of , that is, solving the optimal computation offloading decision in the current time slot.
首先,在第t个时隙开始时,获取当前时隙海洋传感设备所请求计算任务的任务请求指示值(任务请求指示值的取值为{0,1},代表是否获取到计算任务)、海洋传感设备的电池能量水平和海洋传感设备访问雾节点的信道功率。First, at the beginning of the tth time slot, obtain the task request indication value of the computing task requested by the ocean sensing device in the current time slot (Task request indication value The value of is {0, 1}, indicating whether the computing task is obtained), the battery energy level of the ocean sensing device and channel power for ocean sensor devices to access fog nodes .
其次,根据上述获取的当前时隙的信息,代入化简后的计算卸载模型的目标函数中进行求解,求解得到由多维向量构成的解,即确定计算卸载模型的指标、CPU周期的预定频率、海洋传感设备访问雾节点的发射功率基于能量收集技术到达海洋传感设备的部分能量。其中,化简后的计算卸载模型如下式所示:Secondly, according to the information of the current time slot obtained above, it is substituted into the objective function of the simplified computation offloading model for solving, and the solution consisting of multi-dimensional vectors is obtained, that is, the index of the computation offloading model is determined. , the predetermined frequency of CPU cycles , Transmission power of marine sensor equipment accessing fog nodes Part of the energy reaching ocean sensing devices based on energy harvesting technology Among them, the simplified calculation offloading model is shown as follows:
s.t.s.t.
之后,根据计算确定的结果更新海洋传感设备的电池能量队列,即更新,并判断是否达到当前时隙的稳定值,即判断是否满足计算卸载模型的约束条件,若满足,则认为达到当前时隙的稳定值,将计算确定的结果作为当前时隙内的最优计算卸载决策输出;否则计算下一时隙的最优计算卸载决策。Afterwards, the battery energy queue of the ocean sensor device is updated according to the calculated result, that is, the battery energy queue of the ocean sensor device is updated. , and judge whether the stable value of the current time slot is reached, that is, judge whether the constraints of the computational offloading model are met. If so, it is considered that the stable value of the current time slot is reached, and the result determined by the calculation is output as the optimal computational offloading decision in the current time slot; otherwise, the optimal computational offloading decision for the next time slot is calculated.
考虑到海洋传感设备的资源(计算、存储和能源)及海洋节点动态拓扑的限制,传统卸载方法无法适用,因此,本实施例提供了一种基于李雅普诺夫(Lyapunov)优化的动态计算卸载策略,该策略复杂度低,适配海洋节点的弱计算能力,充分利用各海洋节点的能源和计算能力,对计算任务进行更加合理的分配,从而达到减小平均决策时延和系统能耗的目的,保证服务质量QoS。Considering the limitations of the resources (computing, storage and energy) of marine sensor equipment and the dynamic topology of marine nodes, traditional offloading methods are not applicable. Therefore, this embodiment provides a dynamic computing offloading strategy based on Lyapunov optimization. This strategy has low complexity, adapts to the weak computing power of marine nodes, makes full use of the energy and computing power of each marine node, and allocates computing tasks more reasonably, thereby achieving the purpose of reducing the average decision delay and system energy consumption, and ensuring the quality of service QoS.
实施例二Embodiment 2
本实施例提供了一种基于能量收集技术的海洋传感网络计算卸载系统,包括:This embodiment provides a marine sensor network computing unloading system based on energy harvesting technology, including:
信息获取模块,用于在每一时隙内,获取当前时隙海洋传感设备的实时信息,所述实时信息包括海洋传感设备所请求计算任务的任务请求指示值、海洋传感设备访问雾节点的信道功率以及海洋传感设备的电池能量水平;An information acquisition module is used to acquire real-time information of the ocean sensor device in the current time slot in each time slot, wherein the real-time information includes a task request indication value of the computing task requested by the ocean sensor device, a channel power for the ocean sensor device to access the fog node, and a battery energy level of the ocean sensor device;
模型构建模块,用于构建海洋传感设备在当前时隙内执行计算任务的计算延迟和能量消耗,以及将计算任务卸载至雾节点的传输时延和能量消耗,搭建计算任务执行成本模型、海洋传感设备能耗模型和能量收集模型,以长期平均执行成本最小为目标函数,结合所搭建的模型,构建计算卸载模型;The model building module is used to construct the computational delay and energy consumption of the ocean sensor equipment in executing the computational task in the current time slot, as well as the transmission delay and energy consumption of offloading the computational task to the fog node, build the computational task execution cost model, the ocean sensor equipment energy consumption model and the energy collection model, and build the computational offloading model with the minimum long-term average execution cost as the objective function in combination with the built model;
卸载决策求解模块,用于根据所获取的实时信息,利用动态算法求解计算卸载模型,求解获得当前时隙的最优计算卸载决策。The offloading decision solving module is used to solve the computing offloading model using a dynamic algorithm based on the acquired real-time information, and to obtain the optimal computing offloading decision for the current time slot.
以上实施例二中涉及的各步骤与方法实施例一相对应,具体实施方式可参见实施例一的相关说明部分。The steps involved in the above embodiment 2 correspond to those in the method embodiment 1. For the specific implementation method, please refer to the relevant description part of the embodiment 1.
本领域技术人员应该明白,上述本发明的各模块或各步骤可以用通用的计算机装置来实现,可选地,它们可以用计算装置可执行的程序代码来实现,从而,可以将它们存储在存储装置中由计算装置来执行,或者将它们分别制作成各个集成电路模块,或者将它们中的多个模块或步骤制作成单个集成电路模块来实现。本发明不限制于任何特定的硬件和软件的结合。Those skilled in the art should understand that the modules or steps of the present invention described above can be implemented by a general-purpose computer device, or alternatively, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. The present invention is not limited to any specific combination of hardware and software.
以上所述仅为本发明的优选实施例而已,并不用于限制本发明,对于本领域的技术人员来说,本发明可以有各种更改和变化。凡在本发明的精神和原则之内,所作的任何修改、等同替换、改进等,均应包含在本发明的保护范围之内。The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
上述虽然结合附图对本发明的具体实施方式进行了描述,但并非对本发明保护范围的限制,所属领域技术人员应该明白,在本发明的技术方案的基础上,本领域技术人员不需要付出创造性劳动即可做出的各种修改或变形仍在本发明的保护范围以内。Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Technical personnel in the relevant field should understand that various modifications or variations that can be made by technical personnel in the field without creative work on the basis of the technical solution of the present invention are still within the scope of protection of the present invention.
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