面向大型提升装备制动过程的刚柔耦合动力响应机理及平稳制动策略研究

The brake system is an important part of a large hoist. It has a significant impact on the production efficiency and safe operation of the large hoist. With the characteristics of flexible transmission by wire rope, high speed, big inertia and large elevated distance, severe shock and vibration could easily occur when the large hoist is braked. Sometimes brake shock and vibration even lead to wire rope slipping and fracturing. However, the existing constant deceleration braking strategy can’t effectively suppress the brake shock and vibration on all kinds of operating conditions. To solve this problem, the project proposes a novel smooth braking strategy which adopts different braking modes depending on the operating parameters at the beginning of the brake process. In order to improve the performance of the braking system, a double-closed-loop three-way proportional pressure reducing valve controlling hydraulic circuit is also presented. A multidisciplinary model for the lifting system and braking system considering rigid-flexible coupling effect is created to explore the dynamic response characteristics of the lifting system during the braking process. Adaptive deceleration braking model based on extreme learning machine is established to predict the appropriate deceleration value. The input variables of the model are operating parameters of the lifting system at the beginning of the brake process, the output result of the model is the brake deceleration value. A laboratory load performance test system is constructed to validate the above-mentioned braking method and corresponding hydraulic circuit. The research will provide a new solution for the smooth braking system of the large hoist and analogous flexible transmission systems. Moreover, the associated research results can also lay the foundation for the development of the super large flexible transmission equipment braking system.

制动系统是大型提升装备的重要组成部分，对其生产效率和安全运行有着重要影响。大型提升装备具有钢丝绳柔性传动、速度快、惯性大和提升落差大等特点，导致其在制动过程中极易产生剧烈的冲击和振动，严重时可造成钢丝绳打滑或断裂。本项目针对上述问题，为克服现有制动策略存在的不足，提出一种基于提升系统制动初始运行参数的自适应平稳制动策略，并为之构建了基于双闭环三通比例减压阀的制动回路，为其提供硬件保障。通过建立制动、提升系统刚柔耦合动力学仿真模型，获得制动过程中提升系统的刚柔耦合动力响应规律；以此为基础，建立以制动初始运行参数为输入变量，制动减速度为输出的极限学习机自适应减速制动模型，实现对任意工况下最优制动减速度的预测；构建提升重物负载模拟的带载制动性能测试系统，实验验证所提出方法的正确性。项目为大型提升装备和具有柔性传动特性系统的平稳制动提供了新的解决思路，为实现超大规格柔性传动设备的平稳制动奠定基础。

矿井提升机采用钢丝绳传动方式，因此在紧急制动过程中极易产生冲击与振动，严重可致钢丝绳打滑和断裂。为减小提升系统冲击与振动，项目对三通比例减压阀及其制动回路、比例流量阀死区补偿、提升系统建模与动力学特性分析、极限减速度预测，以及模拟试验台研制与测试等开展了研究。获得以下成果或结论：(1) 研制了液压阀比例放大器，加工了三通比例减压阀，静态压力曲线具有良好线性度，滞环小于1%，压力阶跃响应时间满足使用要求；(2) 提出并验证了2种比例流量阀死区补偿策略，以减小无位移传感器比例流量阀死区、提高控制精度；(3) 基于三通比例减压阀的提升系统纵向振动幅值小于传统比例流量阀控制的提升系统纵向振动幅值，前者在紧急制动工况下的最大振幅不到后者的1/2；(4) 建立了制动－提升系统刚柔耦合的机电液联合仿真模型，可对系统动力学关键特征进行预测，仿真和试验结果表明无论是正常减速制动还是恒减速紧急制动，纵向振动均是主要振动分量，频率小于10 Hz；对于恒减速制动，若钢丝绳未打滑，振动曲线在制动过程中将以给定减速度值为平衡点作有阻尼衰减振荡，制动末期系统将先产生一个峰值，然后呈现出与正常制动末期类似的振动特性；否则，纵向振动特征将明显区别于未打滑条件下的振动特征。基于标准逻辑函数对提升机运行轨迹进行优化，相较于传统四阶多项式轨迹，提升工况下纵向振动减小了10.85%，最大动张力减小了9.06%；(5) 基于系统纵向振动特征，提出并验证了一种确定极限减速度的新方法，经线性拟合后得到极限减速度预测模型，a = -c×M + b（下放工况）和d = -e×M + f（提升工况）；(6) 建立提升机极限减速度的回归模型和打滑现象的分类模型，结果表明打滑现象预测模型的预测准确率为89.5%。（6）研制了矿井提升机惯性试验台研制，测试表明紧急制动工况下制动力矩波动剧烈，大约是正常静力矩的2-3倍。上述研究结果将为摩擦提升机的结构设计、运行参数优化、减振抑振，以及故障诊断提供依据。