Fuzzy Sliding Mode Control for the Vehicle Height and Leveling Adjustment System of an Electronic Air Suspension

The accurate control for the vehicle height and leveling adjustment system of an electronic air suspension(EAS) still is a challenging problem that has not been effectively solved in prior researches. This paper proposes a new adaptive controller to control the vehicle height and to adjust the roll and pitch angles of the vehicle body(leveling control) during the vehicle height adjustment procedures by an EAS system. A nonlinear mechanism model of the full?car vehicle height adjustment system is established to reflect the system dynamic behaviors and to derive the system optimal control law. To deal with the nonlinear characters in the vehicle height and leveling adjustment processes, the nonlinear system model is globally linearized through the state feedback method. On this basis, a fuzzy sliding mode controller(FSMC) is designed to improve the control accuracy of the vehicle height adjustment and to reduce the peak values of the roll and pitch angles of the vehicle body. To verify the effectiveness of the proposed control method more accurately, the full?car EAS system model programmed using AMESim is also given. Then, the co?simulation study of the FSMC performance can be conducted. Finally, actual vehicle tests are performed with a city bus, and the test results illustrate that the vehicle height adjustment performance is effectively guaranteed by the FSMC, and the peak values of the roll and pitch angles of the vehicle body during the vehicle height adjustment procedures are also reduced significantly. This research proposes an effective control methodology for the vehicle height and leveling adjustment system of an EAS, which provides a favorable control performance for the system.

Early clinical outcome with lens position adjustment following implantable collamer lens surgery

AIM:To observe early clinical outcome with lens position adjustment following the implantable collamer lens(ICL)surgery.METHODS:Sixty patients were selected for this retrospective study.One eye from each patient received Toric ICL for astigmatism correction,and the other received non-astigmatic ICL surgery using horizontal position.Patients with higher postoperative arch height were selected,and their non-astigmatic eye clinical outcome were observed after ICL surgery at 1wk,1,and 3mo.The clinical measurements included uncorrected visual acuity(UCVA),intraocular pressure(IOP),refractive state,corneal endothelium cell count,and arch height.Three months later,the ICL in each patient’s non-astigmatic eye was adjusted to the vertical from the horizontal position.The results were compared before and 1wk,1,and 3mo after adjustment.RESULTS:UCVA and IOP were significantly reduced 1wk after position adjustment compared to 1wk after ICL implantation(P<0.05).The patients demonstrated significantly reduced arch height and corneal endothelium cell count 1wk,1,and 3mo after adjusting position compared to 1wk,1,and 3mo after ICL implantation(P<0.05).However,there was no significant difference in refraction between 1wk,1,and 3mo after ICL implantation and position adjustment(P>0.05).CONCLUSION:Early positioning adjustment postphakic ICL implantation can benefit patients with adjusted arch height or higher IOP.Despite the good clinical effects,the doctors should pay attention to the potential for adverse effects on UCVA and corneal endothelium cells following early position adjustment after posterior chamber phakic ICL implantation.

Complex Least Squares Adjustment to Improve Tree Height Inversion Problem in PolInSAR

At present,the principal data processing methods involving complex observations are based on two strategies according to characteristics of the observation process,i.e.,step-by-step and direct resolution.However,these strategies have some limitations,e.g.they cannot consider statistical observation error information,redundant observations and so on.This paper applies least squares methods to complex data processing to extend surveying adjustment theory from real to complex number space.We compared the two adjustment criteria for a complex domain in a quantitative way.In order to understand the effectiveness of complex least squares,tree height inversion from PolInSAR data is taken as an example.We firstly established both a complex adjustment function model and a stochastic model for PolInSAR tree height inversion,and then applied the complex least squares method to estimate tree height.Results show that the complex least squares approach is reliable and outperforms other classic tree height retrieval methods;the method is simple and easy to implement.

Research of Sail Height Adjustment on Sail-Assisted Ship in Different Loading and Wind Conditions

The relationship between ship stability and sail area is firstly investigated based on the sail-assisted ship＇s stability in this paper. Then a height-adjustable sail structure is proposed that could be automatically adjusted according to the wind conditions, ship loading and other requirements. The influences on the sail height in different ship load conditions, different wind apparent velocity and wind direction are analyzed of a sail-assisted bulk carrier. Finally a control procedure of sail height adjustment in real time is proposed according to the actual load conditions, wind conditions, ship velocity and other parameters to make the best use of wind energy, which is significant for the practical application of sail-assisting technology in the future.

Control strategy for an intelligent shearer height adjusting system

An intelligent shearer height adjusting system is a key technology for mining at a man-less working face. A control strategy for a shearer height adjusting system based on a mathematical model of the height adjusting mechanism is proposed. It considers the non-linearity and time variations in the control process and uses Dynamic Fuzzy Neural Networks （D-FNN）. The inverse characteristics of the system are studied. An adaptive on-line learning and error compensation mechanism guarantees sys- tem real-time performance and reliability. Parameters from a German Eickhoff SL500 shearer were used with Maflab/Simulink to simulate a height adjusting control system. Simulation shows that the trace error of a D-FNN controller is smaller than that of a PID controller. Also, the D-FNN control scheme has good generalization and tracking performance, which allow it to satisfy the needs of a shearer height adjusting system.

Self-Adaptive Control System for Additive Manufacturing Using Double Electrode Micro Plasma Arc Welding

Wire arc additive manufacturing(WAAM)has been investigated to deposit large-scale metal parts due to its high deposition efficiency and low material cost.However,in the process of automatically manufacturing the high-quality metal parts by WAAM,several problems about the heat build-up,the deposit-path optimization,and the stability of the process parameters need to be well addressed.To overcome these issues,a new WAAM method based on the double electrode micro plasma arc welding(DE-MPAW)was designed.The circuit principles of different metal-transfer models in the DE-MPAW deposition process were analyzed theoretically.The effects between the parameters,wire feed rate and torch stand-off distance,in the process of WAAM were investigated experimentally.In addition,a real-time DE-MPAW control system was developed to optimize and stabilize the deposition process by self-adaptively changing the wire feed rate and torch stand-off distance.Finally,a series of tests were performed to evaluate the control system’s performance.The results show that the capability against interferences in the process of WAAM has been enhanced by this self-adaptive adjustment system.Further,the deposition paths about the metal part’s layer heights in WAAM are simplified.Finally,the appearance of the WAAM-deposited metal layers is also improved with the use of the control system.

OPTIMIZING DESIGN OF MECHANICAL SELF-CENTERING DEVICE FOR SUSPENSION HEIGHT

Firstly, in view of the respective defects of existing self-centering devices for vehicle suspension height, the design scheme of the proposed mechanical self-centering device for suspension height is described. Taking the rear suspension of a certain light bus as a research example, the structures and parameters of the novel device are designed and ascertained. Then, the road excitation models, the performance evaluation indexes and the half-vehicle model are built, the simulation outputs of time and frequency domain are obtained with the road excitations of random and pulse by using MATLAB/Simulink software. So the main characteristics of the self-centering suspension are presented preliminarily. Finally, a multi-objective parameter design optimization model for the self-centering device is built by weighted sum approach, and optimal solution is obtained by adopting complex approach. The relevant choosing-type parameters for self-centering device components are deduced by using discrete variable optimal method, and the optimal results are verified and analyzed. So the performance potentials of the self-centering device are exerted fully in condition of ensuring overall suspension performances.

基于改进门控循环神经网络的采煤机滚筒调高量预测

采煤机自适应截割技术是实现综采工作面智能化开采的关键技术。针对采煤机在复杂煤层下自动截割精度较低的问题,提出了一种基于改进门控循环神经网络(GRU)的采煤机滚筒调高量预测方法。鉴于截割轨迹纵向及横向相邻数据之间的相关性,采用定长滑动时间窗法对获取的采煤机滚筒高度数据进行预处理,将输入数据划分为连续、大小可调的子序列,同时处理横向、纵向的特征信息。为提高模型预测效率,满足循环截割的实时性要求,提出了一种用因果卷积改进的门控循环神经网络(CC-GRU),对输入数据进行双重特征提取和双重数据过滤。CC-GRU利用因果卷积提前聚焦序列纵向的局部时间特征,以减少计算成本,提高运算速度;利用门控机制对卷积得到的特征进行序列化建模,以捕捉元素之间的长期依赖关系。实验结果表明,采用CC-GRU模型对采煤机滚筒调高量进行预测,平均绝对误差(MAE)为43.80 mm,平均绝对百分比误差(MAPE)为1.90%,均方根误差(RMSE)为50.35 mm,决定系数为0.65,预测时间仅为0.17 s;相比于长短时记忆(LSTM)神经网络、GRU、时域卷积网络(TCN),CC-GRU模型的预测速度较快且预测精度较高,能够更准确地对采煤机调高轨迹进行实时预测,为工作面煤层模型的建立和采煤机调高轨迹的预测提供了依据。

新型有轨电车扣件系统设计及性能

针对国内有轨电车无枕式扣件调高量不足、共享路权地段扣件强度尚待加强等问题,提出了一种新型有轨电车扣件系统,并对该扣件进行了有限元分析和室内试验。该扣件系统为弹性不分开式有挡肩扣件,其中基板和调高座采用玻纤增强聚酰胺材料注塑成型,在保证承载力的前提下提高了基板和调高座的防腐蚀性和绝缘减振性;其余零部件为国铁标准件或地铁通用件。该扣件垂向调整量为0~+20 mm,轨距调整量为-12~+8 mm,调整极差为1 mm。计算和试验结果表明:本文研发的新型有轨电车扣件系统关键零部件受力和变形满足要求,结构可靠;300万次荷载循环后各零部件无损伤,无失效;能满足有轨电车对扣件系统调整量、强度和可靠性的要求,性能稳定,维修养护方便。将该扣件系统应用于实际工程,通车运营三年,服役状态良好。

基于PLC和工业机器人的激光切割系统应用设计

洗衣机内胆质检过程中,需按照不同型号的产品切割内胆不同部位进行拉力强度试验。为解决人工切割试件质量不稳定,操作安全性低等问题,提出了基于PLC、工业机器人和调高器的激光切割系统,工业机器人夹持调高器与激光切割头,调高器快速跟随调节激光切割头的位置高度,保证了切割试件的质量。实践应用表明,该系统提升了试件的质量,操作安全性好,为质检的准确性提供了保障,具有较高的应用价值。

基于粒子群模糊PID的采煤机自动调高控制系统研究

针对传统PID调高控制精度低和延时长的问题,引入粒子群模糊控制理论,改善系统输出的准确性和跟踪性能。首先研究了采煤机自动调高系统的数学模型,然后分析传统PID和粒子群模糊PID算法的原理,设计了粒子群模糊PID控制器,最终使用Simulink进行仿真。结果表明,相比于传统PID和模糊PID算法,该方法在准确性、快速性和抗干扰能力上都有所提高。

基于可调叶高扩压器的离心压气机构型流动机理研究

离心叶轮/扩压器匹配关系恶化直接限制了离心压气机的稳定工作范围.以Radiver离心压气机为研究对象,借助经过校核的数值模拟方法开展了基于可调叶高扩压器的离心压气机叶轮/扩压器匹配关系及流动机理研究.结果表明:通过建立能够指导扩压器叶高调节方向和量值的“压气机工作流量-扩压器最佳叶高”正相关对应关系,即可在压气机近失稳点等小流量点主动降低扩压器叶高以改善压气机稳定工作裕度.在设计转速下,引入可调叶高扩压器能够使离心压气机的稳定裕度提升18.8%、流量范围拓宽385%且峰值效率提高0.45%;随着压气机工作点向小流量工况偏移,降低扩压器叶高可以抑制扩压器来流正攻角,优化重构其通道内部涡系结构,减小扩压器吸力面和压力面/轮毂角区的低速区,进而改善叶轮/扩压器匹配关系,抑制扩压器内部流动失稳发生,提升离心压气机稳定裕度和效率指标.

基于截割顶底板高度预测模型的采煤机自动调高技术

传统的煤层截割路径规划通过几何控制、规划计算等方式对采煤机滚筒高度进行预测,但存在预测的数据误差较大、无法适应地质条件变化的问题。针对上述问题,提出了一种基于截割顶底板高度预测模型的采煤机自动调高技术。首先,分析了影响截割顶底板高度的因素,指出影响顶底板高度的主要因素包括煤层的起伏变化数据、历史截割数据、刮板输送机的高程数据及人工操作记录,将上述4类数据融合处理,建立以长短期记忆(LSTM)模型和灰色马尔可夫模型为基础的截割顶底板高度预测模型,通过算法模型预测出截割顶底板的高度。然后,以截割顶底板的高度数据为基础,结合采煤机位姿和空间坐标,建立计算滚筒高度的几何模型,同时依据刮板输送机上窜下滑量及是否执行加减刀工艺等因素进行修正,最终将顶底板高度序列转换为滚筒高度序列,即将截割顶底板高度转换为采煤机滚筒的目标高度,由采煤机执行到目标高度,实现滚筒自动调高工业性试验结果表明:(1)在自动调高技术的控制下,顶滚筒和底滚筒的预测高度与实际高度偏差值有90%的数据量均在10 cm以内,滚筒的预测高度和实际高度具有明显的一致性。(2)与传统手动控制方式相比,中部截割一刀煤的人工干预调高次数由49次下降为21次,说明截割顶底板的高度预测模型和计算滚筒高度的几何模型是准确合理的,采煤机滚筒的自动调高技术是可行的。

Modeling and test on height adjustment system of electrically-controlled air suspension for agricultural vehicles

To reduce the damages of pavement,vehicle components and agricultural product during transportation,an electric control air suspension height adjustment system of agricultural transport vehicle was studied by means of simulation and bench test.For the oscillation phenomenon of vehicle height in driving process,the mathematical model of the vehicle height adjustment system was developed,and the controller of vehicle height based on single neuron adaptive PID control algorithm was designed.The control model was simulated via Matlab/Simulink,and bench test was conducted.Results show that the method is feasible and effective to solve the agricultural vehicle body height unstable phenomenon in the process of switching.Compared with other PID algorithms,the single neuron adaptive PID control in agricultural transport vehicle has shorter response time,faster response speed and more stable switching state.The stability of the designed vehicle height adjustment system and the ride comfort of agricultural transport vehicle were improved.

可调高式无砟轨道结构研究

针对无砟轨道基础变形适应能力小的难题,提出一种可调高式无砟轨道结构,由“扣件+垫板”组成,能够灵活调节轨道结构高度,主动适应轨下基础变形。建立可调高式无砟轨道结构整体受力分析有限元模型,分析轨道结构合理尺寸;建立轨道局部受力计算模型,分析垫板厚度变化的影响及锚固螺栓受力状态。结果表明:轨枕块高度为200 mm,埋深为140 mm时,各部件受力较小;通过更换不同厚度的垫板能够实现轨道结构0~60 mm的垂向调整量;锚固螺栓能够正常工作,满足强度设计要求。

Inversion of vegetation height from Pol In SAR using complex least squares adjustment method

In this paper, we propose the novel method of complex least squares adjustment （CLSA） to invert vegetation height accurately using single-baseline polarimetric synthetic aperture radar interferometry （PollnSAR） data. CLSA basically estimates both volume-only coherence and ground phase directly without assuming that the ground-to-volume amplitude radio of a particular polarization channel （e.g., HV） is less than -10 dB, as in the three-stage method. In addition, CLSA can effectively limit errors in interferometric complex coherence, which may translate directly into erroneous ground-phase and volume-only coherence estimations. The proposed CLSA method is validated with BioSAR2008 P-band E-SAR and L-band SIR-C PollnSAR data. Its results are then compared with those of the traditional three-stage method and with external data. It implies that the CLSA method is much more robust than the three-stage method.

采煤机滚筒调高控制系统设计

针对采煤机滚筒调高系统自动化水平低、控制精度不高的问题,提出基于微控制器处理器、先进控制算法的采煤机滚筒调高系统设计方案。以STM32F103RCT6为中央处理器,采用预见前馈补偿控制算法对采煤机滚筒进行精确控制;搭建实验平台并完成给定目标路径斜率跟踪实验、给定目标路径跟踪实验。实验结果表明,设计的采煤机滚筒调高控制系统自动化水平高、响应快、控制精度高,稳态时跟踪误差满足采煤机调高控制系统精度要求。

光伏运维操作平台的设计与应用

阐述一种基于实战化技术培训的光伏运维员操作平台的设计,该操作平台通过在其支撑支架内部设置升降机构,实现高度调节功能。操作平台有延长机构、限位机构,满足光伏电站运维各类项目的实战化训练,也是相关课程实践教学设施设备的补充。

基于工艺驱动的采煤机智能截割调控

传统采煤机截割调控缺乏对采煤机滚筒状态的分析,导致截割模板生成质量低;未充分考虑工作面起伏情况和地质环境条件,无法得到最优截割路径;依赖采煤机自身控制单元无法及时调整滚筒高度。针对上述问题,提出了一种基于工艺驱动的采煤机智能截割调控方案。按照工作面液压支架编号,实时采集对应的滚筒截割高度数据,并结合滚筒截割高度历史数据对实时数据进行处理,生成符合工作面顶底板曲线趋势的采煤机截割模板;基于工作面顶底板写实数据、人工割煤经验,规划采煤机截割路径并进行实时干预,实现采煤机滚筒截割高度与工作面顶底板曲线的自适应耦合;通过编辑采煤工艺和设置截割模板数据,形成采煤工艺表文件,并依此调节采煤机滚筒截割高度,实现采煤机自适应调高控制。基于工艺驱动的采煤机智能截割调控方案应用于神东煤炭集团榆家梁煤矿43207工作面,实现了无人化采煤常态化作业,将生产班工作面作业人员由3人减少至工作面中部无人,采煤机自动割煤率达97%以上。

采煤机调高试验装置的设计

为了充分验证当前煤岩识别和采煤机自适应调高控制技术的应用效果,提出采用采煤机调高试验装置进行模拟试验的思路。在完成采煤机调高试验装置总体设计的基础上,重点对采煤机调高试验装置的截割系统和液压系统进行设计,完成了截割电机、减速装置以及调高油缸的设计,为完成采煤机调高试验装置的研发奠定扎实理论基础。