超高速水下航行器航向控制研究

超高速水下航行器在水下航行时,表面大部分被超空泡所包覆,其运动特性发生显著变化,使得其工况变得更为复杂、控制难度加大;通过分析它的运动特点,建立了系统模型方程,并提出把空化器作为控制面,通过操纵其舵角改变量来控制航行器航向;最后运用PI极限舵控制算法进行仿真分析,结果表明此控制方法简单易实现,产生的偏差小,同时还提高了系统的响应速度,较好地满足了系统要求,分析结论可为超高速水下航行器控制系统设计提供参考。     

一种新型的超空泡航行器流体动力布局

超高速水下航行器运行于巡航阶段,为减小其阻力,减小航行器的沾湿部分,会使得横滚运动的阻尼变小,加大横滚通道的控制难度.针对航行器的静稳定特性,采用艏部空化器作为俯仰和偏航运动的操纵面.由于横滚干扰力矩主要来源于航行器机动时产生的离心力,采用不对称方向舵的方式来消除横滚干扰力矩.复合抗横滚控制舵片形成方向舵的上下不平衡,同时还作为横滚控制的操纵面.采用流体动力布局形式完全摒弃了尾部安定面和操纵面,明显减小航行器航行阻力,降低横滚控制舵机的功率要求,有利于机构的小型化.同时放宽了对超空泡外形和人工通气量的准确度要求,方便了超高速水下航行器的工程实现.     

超高速水下航行器纵平面姿态控制研究

超高速水下航行器在水下航行时,由于大部分表面被超空泡所包覆,其纵平面的运动特性发生显著变化,使得控制难度加大.提出把空化器用作控制面,通过操纵其舵角改变量来控制航行器在纵平面的运动,从而达到间接控制航深的目的.最后运用PID算法进行仿真分析,结果表明采用此控制方法所产生的深度负偏差较小,简单易实现、且鲁捧性好.还对航行器直接深度控制进行探讨,考虑到超空泡工况下深度测量的难度较大,姿态控制具有更强的适用性.     

水下超高速航行器首舵控制系统的设计

水下超高速航行器处于巡航阶段时,由于其大部分表面被超空泡包裹,运动模式不同于常规的全沾湿航行器;为了对超高速水下航行器的定深弹道实施控制,在研究水下超高速航行器运动模型的基础上,对首舵机控制系统的控制率进行了综合,研制了一种新型的深度间接控制的电动首舵机闭环控制系统;详细介绍了功率控制单元的工作原理、硬件设计的关键技术及控制软件设计;地面考核试验证明该控制系统完全满足超高速航行器的姿态控制要求;研究结果可为水下超高速航行器控制系统的设计提供参考。     

水下航行器X字型舵面故障分析与仿真

X字型舵水下航行器与十字型舵水下航行器相比,舵机系统具有功能冗余性.目前国内对舵机系统的故障诊断主要是针对十字型舵,而对于X字型舵的研究还比较少.针对上述情况,论文分析了X字型舵与十字型舵水下航行器舵面布局的差异以及X字型舵水下航行器流体动力特性,建立了X字型舵水下航行器力及力矩模型,研究了X字型舵在舵面故障情况下动力特性的改变,给出了X字型舵舵面损伤时横滚角的动态变化.仿真结果表明,X字型舵水下航行器在舵面损伤时横滚角趋于发散,通过设置合适的观测器,就能检出该故障,对进一步研究X字型舵水下航行器的故障诊断具有重要的作用.     

基于PC104的超高速水下航行器测控程序设计与实现

超高速水下航行器自主航行试验需要雷载计算机提供时序控制、姿态自动控制等支持,在恶劣水下环境中测控系统的可靠性至关重要,它影响着实航数据的获取和航行控制研究的开展.以PC104嵌入式计算机为硬件平台,标准C语言为开发工具,针对超高速水下航行器航行控制和数据测量需求开发了测控程序.通过电平I/O进行时序及航行姿态控制,串口...     

机动超空泡水下航行器纵平面运动特性分析

超空泡水下航行器机动运动由于有空泡的时间延迟效应和重力效应的存在,使得航行器与直航超空泡航行器的运动特性有很大的不同;进行纵平面运动分析,是对航行器实施深度控制和姿态控制的前提;考虑时间延迟效应和重力效应引起的空泡轴变形,建立超空泡航行器机动航行纵平面运动模型,推导纵平面运动传递函数,并以某小口径(约200mm)超空泡水下航行器的特征参数为例分析其运动特性;纵平面运动特性分析为超空泡水下航行器机动运动的系统设计和控制提供了重要参考。     

超空泡水下航行器定深控制研究

极高的航速使得对超空泡水下航行器的控制变得异常复杂. 为了对其深度进行有效控制, 必须对其纵平面运动特性进行研究. 本文首先建立了超空泡水下航行器的纵平面运动模型, 分析了其纵平面运动特性; 然后进行了控制算法的综合; 最后, 仿真及试验结果均验证了所设计的航行器纵平面运动控制算法的有效性. 试验结果表明该控制系统具有较高的控制精度. 本文的研究成果为进一步研究水下超空泡航行器的运动控制提供了必要的理论基础.     

海浪扰动下水下航行器的动力定位性能分析

水下航行器动力定位是通过对水下航行器的多个螺旋桨推进器的转速、推力进行控制调节以抵御外界环境扰动,体现了水下航行器在外界环境扰动下执行各种任务的能力.通过对随机波浪扰动下的水下航行器前向动力定位进行建模仿真,分析得到各个状态特性与环境扰动分量对水下航行器动力定位性能的影响.进行了水下航行器的运动方程和螺旋桨动力学特性的精确建模;再针对波频扰动下的变参数问题以及控制器的鲁棒性和自适应性要求,建立了水下航行器动力定位滑模控制器;最后,将PM谱的随机波浪扰动应用于动力定位仿真研究,仿真结果显示,螺旋桨的动力学特性、幅值限制以及波浪的流速与加速度信息直接影响了水下航行器的动力定位性能.     

基于MSP430的遥控无人水下航行器控制系统设计

针对某型遥控无人水下航行器,给出了总体结构和系统组成;在此基础上,基于MSP430微控制器,给出了某型低功耗的无人水下航行器控制系统的总体设计方案,采用H桥电路实现对航行器电机的控制,用nRF905单片无线收发器进行通信实现遥控控制,并进行了软件的详细设计与调试。水池试验结果表明,某型无人遥控水下航行器以约0.5m/s的速度前进时,运行情况良好,并基本实现了拐弯、下潜和上升等各预期功能,最后得出了该控制方案是可行的结论。     

Robust roll motion control of a vehicle using integrated control strategy

This paper presents an electrically actuated roll motion control of a vehicle using simulation and experimental analysis. The controller is designed with an H_∞ control scheme based on the 3 DOF vehicle model considering parameter variations, which affect the roll dynamics. To investigate the feasibility of the active roll control system, its performance is evaluated by simulation in a full vehicle model under various conditions. The Hil setup with the electrically actuated roll control system was devised and its performance was investigated through experimental works. Finally, to enhance the performance in a transient region, an integrated control strategy is presented.     

A novel integrated control framework of AFS,ASS, and DYC based on ideal roll angle to improve vehicle stability

The current research on vehicle stability control mainly focuses on following the ideal yaw rate and sideslip angle, without considering the potential of ideal roll angle in improving the vehicle stability. In addition, the mutation of tire-road friction coefficient promotes a great challenge to the stability control. To improve the vehicle stability, in this study, firstly, the three-dimensional stability region of “lateral speed-yaw rate-roll angle” was studied, and a method to determine the ideal roll angle was proposed. Secondly, a novel integrated control framework of AFS, ASS, and DYC based on ideal roll angle was proposed to actively control the front tire slip angles, suspension forces, and motor torques: In the upper-level controller, model predictive control and tire force distribution algorithm were used to obtain the optimal four-tire longitudinal forces, front tire lateral forces and additional roll moment under constraints; In the lower-level controller, the upper virtual target was realized by the optimal allocation algorithm of actuators and the tire slip controller. Finally, the proposed control framework was verified on the varied-µ road. The results indicated that compared with the two existing control strategies, the proposed framework can significantly improve the vehicle following performance and stability.     

Effective Turning Motion Control of Internally Actuated Autonomous Underwater Vehicles

This paper presents a novel roll mechanism and an efficient control strategy for internally actuated autonomous underwater vehicles (AUVs). The developed control algorithms are tested on Michigan Tech’s custom research glider, ROUGHIE (Research Oriented Underwater Glider for Hands-on Investigative Engineering), in a controlled environment. The ROUGHIE’s design parameters and operational constraints were driven by its requirement to be man portable, expandable, and maneuverable in shallow water. As an underwater glider, the ROUGHIE is underactuated with direct control of only depth, pitch, and roll. A switching control method is implemented on the ROUGHIE to improve its maneuverability, enabling smooth transitions between different motion patterns. This approach uses multiple feedforward-feedback controllers. Different aspects of the roll mechanism and the effectiveness of the controller on turning motion are discussed based on experimental results. The results illustrate that the ROUGHIE is capable of achieving tight turns with a radius of 2.4 meters in less than 3 meters of water, or one order of magnitude improvement on existing internally actuated platforms. The developed roll mechanism is not specific to underwater gliders and is applicable to all AUVs, especially at lower speeds and in shallower water when external rudder is less effective in maneuvering the vehicle.     

Robust adaptive backstepping sliding mode control for motion mode decoupling of two‐axle vehicles with active kinetic dynamic suspension systems

A mode decoupling control strategy is proposed for the active Kinetic Dynamic Suspension Systems (KDSS) with electrohydrostatic actuator (EHA) to improve the roll and warp mode performances. A matrix transfer method is employed to derive the modes of body and wheel station motions for full vehicle with active KDSS. The additional mode stiffness produced by the active KDSS is obtained and quantitatively described with the typical physical parameters. A new hierarchical feedback control strategy is proposed for the active KDSS to improve the roll and warp motion performances and simultaneously accounting for nonlinear dynamics of the actuators with hydraulic uncertainties. H∞ static output‐feedback control is employed to obtain the desirable mode forces, and a new projection‐based adaptive backstepping sliding mode tracking controller is designed for EHA to deal with address the nonlinearity and parameters uncertainty. This controller is used to realize the desirable pressure difference of EHA required from the target mode forces. Numerical simulations are presented to compare the roll and warp performances between the active KDSS, conventional spring‐damper suspension, and suspension with antiroll bar under typical excitation conditions. The evaluation indices are normalized and compared with radar chart. The obtained results illustrate that the proposed active KDSS with proposed controller does not produce additional warp motion for vehicle body, and has achieved more reasonable tire force distribution among wheel stations, the roll stability, road holding, and significantly improved ride comfort simultaneously.     

Hybrid attitude control in steering maneuver using ARC Hil setup

This paper presents the design of an active roll controller for a vehicle and an experimental study using an electric actuating roll control system. Firstly, based on a three degrees of freedom linear vehicle model, the controller is designed using lateral acceleration and rollrate feedback. In order to investigate the feasibility of an active control system, experimental work is carried out using a hardware-in-the-loop (Hil) setup which has been constructed using the devised electric actuating system and the full vehicle model including tire characteristics. The performance is evaluated by an experiment using the Hil setup in which steering maneuvers are carried out. Finally, in order to enhance the control performance in a transient region, the hybrid control strategy is proposed and evaluated.     

超空泡航行器极点配置变结构控制方法研究

超空泡航行器在航行过程中，尾部会周期性拍打空泡壁而表现出强烈的“尾拍”现象，尾部空泡是由空化器经历的历史位置形成，呈现强烈的时滞特性，动力学建模和稳定控制是制约其发展的核心难题。针对泡体耦合问题，建立了空泡/刚体相对几何关系一体化实时解算的动力学模型。针对后体非线性特性，采用分段线性化方法，在保留后体尾拍非线性特性的基础上，建立了面向控制的简化模型。为了解决超空泡航行器非线性时滞控制问题，针对弹体运动极其敏感、操纵效率高等特点，采用极点配置的方式将控制模型配置到理想状态。针对尾拍过程非线性和不确定极大的特点，建立了面向扰动的变结构控制器，实现超空泡航行器扰动运动控制。采用极点配置变结构控制方法，分别设计了滚转通道和俯仰通道控制律。利用泡体耦合动力学模型进行6DOF控制闭环轨迹仿真，稳定巡航过程中深度控制误差小于0.1m，滚转角控制误差小于4°，表明该控制方法能够对航行器滚转角和深度实现稳定控制，控制效果较好，能够满足超空泡航行器航行要求。     

考虑侧倾的无人车NMPC轨迹跟踪控制

针对高速行驶工况下,无人车转弯时的侧倾易导致车辆模型非线性程度增加,引起轨迹跟踪精度下降和状态失稳的问题,设计一种考虑车辆侧倾因素,基于非线性模型预测控制(NMPC)的无人车轨迹跟踪控制器.根据拉格朗日分析力学和车辆运动学,考虑车辆侧倾几何学和载荷转移效应,建立考虑侧倾因素的非线性车辆模型,包括车体动力学模型和修正的“Magic Formula”轮胎模型;基于此车辆模型,构建非线性模型预测控制器(NMPC)的预测模型,并设定控制器的线性、非线性约束,以保证车辆的运动状态处于稳定区域内.在Carsim和Simulink联合仿真平台上,验证车辆高速蛇形工况和双移线工况下的轨迹跟踪控制效果,仿真结果显示,所设计的控制器可有效改善高速弯道工况下的跟踪精度和车辆状态稳定性.     

作业型水下机器人姿态调节控制研究

为了解决在作业时水下机器人载体上的机械手伸展过程将会引起载体重心发生变化,导致水下机器人发生纵横倾运动,影响作业效率的问题,考虑到水下机器人控制系统较为复杂,因此引入模糊滑模控制,根据要求设计出一款模糊滑模控制器。利用计算机和MATLAB技术,将水下机器人姿态运动方程与常规PID控制和模糊滑模控制分别结合起来进行仿真分析。仿真结果表明,模糊滑模控制相比于常规PID控制,在机械手关节正弦运动过程中,姿态角下降了20%以上,横倾姿态角度误差减小了30%以上,纵倾姿态角误差也超过了8%以上。在悬停作业过程中,纵横倾姿态角度都下降了30%以上。通过两种不同控制方式的仿真,验证了模糊滑模控制的控制效果要优于常规PID控制,能够取得更好的控制效果,同时利用计算机技术缩短了研究时间、提高了研究效率。     

Detection of Impending Vehicle Rollover with Road Bank Angle Consideration Using a Robust Fuzzy Observer

 This article describes a method of vehicle dynamics estimation for impending rollover detection. We estimate vehicle dynamic states in presence of the road bank angle as a disturbance in the vehicle model using a robust observer. The estimated roll angle and roll rate are used to compute the rollover index which is based on the prediction of the lateral load transfer. In order to anticipate rollover detection, a new method is proposed to compute the time to rollover (TTR) using the load transfer ratio (LTR). The nonlinear model, deduced from the vehicle lateral and roll dynamics, is represented by a Takagi-Sugeno (T-S) fuzzy model. This representation is used to account for the nonlinearities of lateral cornering forces. The proposed T-S observer is designed with unmeasurable premise variables to cater for non-availability of the slip angles measurement. The proposed approach is evaluated using CarSim simulator under different driving scenarios. Simulation results show good efficiency of the proposed T-S observer and the rollover detection method.