Depth control for a deep-sea self-holding intelligent buoy system based on active disturbance rejection control method

The net buoyancy of the deep-sea self-holding intelligent buoy(DSIB)will change with depth due to pressure hull deformation in the deep submergence process.The net buoyancy changes will affect the hovering performance of the DSIB.To make the DSIB have better resistance to the external disturbances caused by the net buoyancy and water resistance,a depth controller was designed to improve the depth positioning based on the active disturbance rejection control(ADRC).Firstly,a dynamic model was established based on the motion analysis of the DSIB.In addition,the extended state observer(ESO)and nonlinear state error feedback controller were designed based on the Lyapunov stability principle.Finally,semi-physical simulations for the depth control process were made by using the ADRC depth controller and traditional PID depth controller,respectively.The results of the semi-physical simulations indicate that the depth controller based on the ADRC can achieve the predefined depth control under the external disturbances.Compared with the traditional PID depth controller,the overshoot of the ADRC depth controller is 1.74%,and the depth error is within 0.5%.It not only has a better control capability to restrain the overshoot and shock caused by the external disturbances,but also can improve intelligence of the DSIB under the depth tracking task.

Depth-Trim Mapping Control of Underwater Vehicle with Fins

Underwater vehicle plays an important role in ocean engineering. Depth control by fin is one of the difficulties for underwater vehicle in motion control. Depth control is indirect due to the freedom coupling between trim and axial motion. It includes the method of dynamic analysis and lift-resistance-coefficient experiment and theory algorithm. By considering the current speed and depth deviation, comprehensive interpretation is used in object-planning instruction. Expected depth is transformed into expected trim. Dynamic output fluctuation can be avoided, which is caused by linear mapping of deviation. It is steady and accurate for the motion of controlled underwater vehicles. The feasibility and efficiency of the control method are testified in the pool and natural area for experiments.

Locomotion and Depth Control of Robotic Fish with Modular Undulating Fins

This paper presents an environmental-friendly robotic system mimicking the undulating fins of a fish.To mimic the actual flexible fin of real fish,a fin-like mechanism with a series of connecting linkages is modeled and attached to the robotic fish,by virtue of a specially designed strip.Each link is able to turn and slide with respect to the adjacent link.These driving linkages are then used to form a mechanical fin consisting of several fin segments,which are able to produce undulations,similar to those produced by the actual fish fins.Owing to the modular and re-configurable design of the mechanical fin,we are able to construct biomimetic robotic fish with various swimming modes by fin undulations.Some qualitative and workspace observations by experiments of the robotic fish are shown and discussed.

Low energy consumption depth control method of self-sustaining intelligent buoy

Aiming at the contradiction between the depth control accuracy and the energy consumption of the self-sustaining intelligent buoy,a low energy consumption depth control method based on historical array for real-time geostrophic oceanography(Argo)data is proposed.As known from the buoy kinematic model,the volume of the external oil sac only depends on the density and temperature of seawater at hovering depth.Hence,we use historical Argo data to extract the fitting curves of density and temperature,and obtain the relationship between the hovering depth and the volume of the external oil sac.Genetic algorithm is used to carry out the optimal energy consumption motion planning for the depth control process,and the specific motion strategy of depth control process is obtained.Compared with dual closed-loop fuzzy PID control method and radial basis function(RBF)-PID method,the proposed method reduces energy consumption to 1/50 with the same accuracy.Finally,a hardware-in-the-loop simulation system was used to verify this method.When the error caused by fitting curves is not considered,the average error is 2.62 m,the energy consumption is 3.214×10^(4)J,and the error of energy consumption is only 0.65%.It shows the effectiveness and reliability of the method as well as the advantages of comprehensively considering the accuracy and energy consumption.

Depth Control for AUV Based on RS-LSSVM

Aimed at uncertainties and model's impreciseness, nonlinearity and time-variability of depth control system in autonomous underwater vehicle (AUV), a depth predictive control method was put forward based on rough set (RS) and least squares support vector machine (LSSVM). By using RS theory, the monitor data attribute of AUV was reduced to eliminate the redundant information and to improve efficiency. Then, LSSVM model was trained by using the reduced rules, and its parameters were optimized by using chaos theory for the higher accurate control. Taken an AUV typed NPS Phoenix as an example, its depth step response, horizontal rudder and pitch change were simulated. The simulation results show that the method improves the model's accuracy and has better real-time response, fault-tolerant ability, reliability and strong anti-interfere capability.

On the Survivability of Self-repairing Control System for a Hybrid Underwater Vehicle

A hybrid remotely operated underwater vehicle( HROV) capable of working to the full ocean depth has been developed. In order for the vehicle to achieve a certain survivability level,a self-repairing control system( SRCS) has been designed. It consists of two basic technologies,fault diagnosis and isolation( FDI) and reconfigurable control. For FDI,a model-based hierarchical fault diagnosis system is designed for the HROV. Then,control strategies which reconfigure the control system at intervals according to information from the FDI system are presented. Combining the two technologies,it can obtain the fundamental frame of SRCS for the HROV. Considering the hazardous underwater environment at the limiting depth and the hybrid operating modes,an assessment of the HROV's survivability is vitally needed before it enters operational service. This paper presents a new definition of survivability for underwater vehicles and develops a simple survivability model for the SRCS. As a result of survivability assessment for the SRCS,we are able to figure out the survivability of SRCS and make further optimization about it. The methodology developed herein is also applicable to other types of underwater vehicles.

Depth and Altitude Control of an AUV Using Buoyancy Control Device

A new method for depth control was developed for a spilled oil and blow out gas tracking autonomous buoy robot called SOTAB-I by adjusting its buoyancy control device. It is aimed to work for any target depth. The new method relies on buoyancy variation model with a depth that was established based on experimental data. The depth controller was verified at sea experiments in the Toyama Bay in Japan and showed good performance. The method could further be adapted to altitude control by combining the altitude data measured from bottom tracking through a progressive depth control. The method was verified at the sea experiments in Toyama in March 2016 and showed that the algorithm succeeded to bring the robot to the target altitude.

Monocular Vision Based Boundary Avoidance for Non-Invasive Stray Control System for Cattle: A Conceptual Approach

Building fences to manage the cattle grazing can be very expensive;cost inefficient. These do not provide dynamic control over the area in which the cattle are grazing. Existing virtual fencing techniques for the control of herds of cattle, based on polygon coordinate definition of boundaries is limited in the area of land mass coverage and dynamism. This work seeks to develop a more robust and an improved monocular vision based boundary avoidance for non-invasive stray control system for cattle, with a view to increase land mass coverage in virtual fencing techniques and dynamism. The monocular vision based depth estimation will be modeled using concept of global Fourier Transform (FT) and local Wavelet Transform (WT) of image structure of scenes (boundaries). The magnitude of the global Fourier Transform gives the dominant orientations and textual patterns of the image;while the local Wavelet Transform gives the dominant spectral features of the image and their spatial distribution. Each scene picture or image is defined by features v, which contain the set of global (FT) and local (WT) statistics of the image. Scenes or boundaries distances are given by estimating the depth D by means of the image features v. Sound cues of intensity equivalent to the magnitude of the depth D are applied to the animal ears as stimuli. This brings about the desired control as animals tend to move away from uncomfortable sounds.

免耕播种机播深智能控制系统设计

免耕播种机作为免耕播种技术的核心装备,播种深度的精准控制直接影响作物的生长发育。为了进一步提高免耕播种机智能控制系统的稳定性,构建免耕播种机播深自动控制系统,系统阐述其工作原理与流程,并对关键控制模块及设备进行设计与选型。系统测试试验表明,该系统通过充分利用先进的传感器和算法技术,系统响应时间在0.12~0.18 s之间,能够根据不同作物和土壤条件,自动调整播种深度,并取得了良好的播种效果和产量表现。

多波束测深声呐自主数据质量监测及门限控制

为满足水面无人艇等海洋无人平台的需求,确保多波束测深声呐系统在无人监控和参数调节下具备可靠自主工作能力,本文提出一种数据质量在线监测及门限参数控制方法。通过建立基于质量和异常因子的监测模型,结合粒子滤波技术,提高海底地形跟踪门限控制抗差性。仿真和湖上试验显示该方法能判定数据有效性、适应地形变化,并提供合理深度门限,适用于多波束测深声呐系统的在线数据质量监测和无人自主控制。

响应快速调峰的磨煤机自动启停控制研究

在新能源大规模并网形势下,火电机组将长期处于调峰模式,磨煤机频繁启停,运行人员工作量大,操作习惯难统一。设计了一套磨煤机自启停控制系统及仿真对象,经过仿真调试、动态调试,自启停系统一次试运成功且长期稳定投运,系统的投用大幅降低了操作强度,实现了操作过程标准化,提升了机组自动化水平和负荷响应能力。

基于深度学习的安顺电网调控OCS系统告警优化方法

为提升安顺电网调控OCS系统告警效果,研究提出了一种基于深度学习的安顺电网调控OCS系统告警优化方法。该方法先基于深度学习理论完成电网调控系统告警架构优化设计,然后基于LSTM模型完成电网调控OCS系统告警状态预测,最后以预测结果为基础,对其告警信号进行分类,完成电网调控OCS系统告警行为优化设计。实验结果表明,应用所提方法进行安顺电网调控OCS系统告警优化后,其告警准更高、响应时间更短,应用效果更好。

Diving control of underactuated unmanned undersea vehicle using integral-fast terminal sliding mode control

The problem of diving control for an underactuated unmanned undersea vehicle(UUV) considering the presence of parameters perturbations and wave disturbances was addressesed.The vertical motion of an UUV was divided into two noninteracting subsystems for surge velocity control and diving.To stabilize the vertical motion system,the surge velocity and the depth control controllers were proposed using backstepping technology and an integral-fast terminal sliding mode control(IFTSMC).It is proven that the proposed control scheme can guarantee that all the error signals in the whole closed-loop system globally converge to the sliding surface in finite time and asymptotically converge to the origin along the sliding surface.With a unified control parameters for different motion states,a series of numerical simulation results illustrate the effectiveness of the above designed control scheme,which also shows strong robustness against parameters perturbations and wave disturbances.

城市水务集团供水全生命周期工控网络安全提升方案

供水是城市关键基础设施之一,关乎居民用水安全,对其安全性和稳定性要求很高。本文对某水务集团水全生命周期工控系统面临的安全风险进行了分析,强调了工业控制安全,从“预警”“监测”“响应”“防护”和“保障”五个维度构建纵深防御体系。

基于可信执行环境的汽车域控系统安全研究

随着汽车技术的不断发展,汽车系统的安全性问题日益突出。传统的汽车系统存在着许多潜在的安全隐患,如远程攻击、车辆数据泄露和未经授权的访问等。为了解决这些问题,研究人员和汽车制造商开始关注可信执行环境的应用。可信执行环境是一种安全的计算环境,它提供了硬件和软件级别的安全保护,可以保护敏感数据和执行关键任务。在汽车域控制器中引入可信执行环境可以有效地提高系统的安全性和可靠性。文章旨在探究基于可信执行环境的汽车域控系统的安全性,研究现有的可信执行环境技术,并分析其在汽车领域的应用价值,以及探讨可信执行环境对汽车域控制器系统安全性的影响。通过深入研究在汽车领域下可信执行环境的应用,可以为汽车制造商和研究人员提供有关如何提高汽车域控制器系统安全性的指导和建议。最终目标是构建更安全、更可靠的汽车系统,保护用户的隐私和数据安全。

果园侧深施肥机结构设计与试验

为了提高果园土壤养分利用效率和施肥精准度,采用模块化设计了一种果园侧深施肥机,主要由肥料箱、输送装置和开沟覆土装置组成,能够实现精准控制施肥量和施肥深度。通过设置传感器和控制器,实现施肥过程中自动调节施肥参数,以适应不同果树生长需求,并通过田间试验验证了施肥机的性能和可靠性。试验结果表明,该施肥机能够有效控制施肥深度和施肥均匀性,减少肥料浪费和环境污染。最后,对试验结果进行了分析和讨论,提出了改进建议和进一步研究的方向,为果园管理提供了科学依据。

建筑机电一体化电气设计要点实践

根据浙江省工程建设标准DB33/1092-2021《绿色建筑设计标准》对20000 m^(2)以上的公共建筑要求做集中控制的建筑设备管理系统和GB51348-2019《民用建筑电气设计标准》对建筑设备一体化监控系统的要求,以某超高层建筑的机电一体化电气设计实践为例,从强弱电设计界面、电气设计范围及设计深度等方面,详细阐述建筑设备一体化监控系统的电气设计要点。

基于自适应模糊PID的小麦播深控制系统研究

针对目前小麦播种机在复杂的田间作业过程中存在的播深一致性和稳定性难以控制等问题,从调节覆土量确定小麦播深的控制角度出发,提出了一种基于播深反馈的模糊PID控制方法,设计了小麦播种机高精度播深控制系统,实现了播深的自动调控,保证了小麦播深的均匀一致性。该系统主要由车载终端、播深检测模块、播前镇压辊检测模块以及播前镇压辊调节机构等4部分组成,能够实现小麦播种机播深的实时检测及调整。通过播深检测模块获取实时播深并作为反馈输入,结合播深预设值,根据专家模糊规则和Mamdani推理法对PID参数进行在线整定得到控制输出量,控制驱动器调整播前镇压辊位置,不断调整作业过程中的覆土量,从而实现对播深的实时精确控制,确保播深的一致性。田间试验结果表明:播种作业过程中,播深存在小范围波动。当设定播深为30 mm、车速为3~5 km/h时,播深平均值为30.13 mm,播深标准差为0.18 mm,播深合格率均值为93%,播深变异系数均值为2.93%。该系统实现了小麦播种机播深均匀一致的实时自适应调控。

种植机械深度控制系统液压油黏度PID算法研究

针对不同温度下使用不同液压油的种植机械种植深度控制系统,提出一种考虑液压油黏度的PID控制算法。首先,采用Ziegler-Nichols(Z-N)第二方法确定PID系数,应用Routh稳定性准则对系数进行优化;其次,采用PID控制器的极点和双零点最小化响应的持续振荡;最后,将算法应用于3种液压油(32号,46号,68号)进行性能验证。仿真结果表明:不考虑黏度的PID控制算法响应速度慢,不满足边界条件,不能对种植深度进行精确控制;考虑黏度的PID算法能精确控制系统比例阀的压力,所有液压油最大压力不超过1.55 MPa,稳定时间不大于0.45 s,稳态误差为0%,最大超调量17.52%,满足设定要求。

免耕播种机播深控制系统的设计

提出了一种针对免耕播种机的播深控制系统设计方案。该方案通过对免耕播种机的深度传感器进行精确测量和实时反馈,结合电液伺服技术和控制算法实现对播种深度的自动控制。该系统设计能保证播种深度的精度和一致性,提高作业效率,降低劳动成本,并减少农业机械对土地的损害。同时,该系统具有可拓展性和灵活性,能适应不同的作业环境和农作物品种。