Control of a hydraulically actuated continuously variable transmission

Vehicular drivelines with hierarchical powertrain control require good component controller tracking, enabling the main controller to reach the desired goals. This paper focuses on the development of a transmission ratio controller for a hydraulically actuated metal push-belt continuously variable transmission (CVT), using models for the mechanical and the hydraulic part of the CVT. The controller consists of an anti-windup PID feedback part with linearizing weighting and a setpoint feedforward. Physical constraints on the system, especially with respect to the hydraulic pressures, are accounted for using a feedforward part to eliminate their undesired effects on the ratio. The total ratio controller guarantees that one clamping pressure setpoint is minimal, avoiding belt slip, while the other is raised above the minimum level to enable shifting. This approach has potential for improving the efficiency of the CVT, compared to non-model based ratio controllers. Vehicle experiments show that adequate tracking is obtained together with good robustness against actuator saturation. The largest deviations from the ratio setpoint are caused by actuator pressure saturation. It is further revealed that all feedforward and compensator terms in the controller have a beneficial effect on minimizing the tracking error.     

插销式液压升降系统概述及其组成

本文介绍了某海洋施工平台插销式液压升降机构的主要组成、工作原理及主要零件的有限元分析结果,介绍了动定环梁式升降机构的动作顺序,最后介绍了升降系统中的液压设备及电控设备组成。     

常见插销式液压升降机构组成及原理

本文介绍了海洋平台升降系统中常见的插销式液压升降机构,介绍了其组成及工作原理。主要包括单步进型升降机构、双步进型升降机构、单双步进复合型升降机构、连续型升降机构。     

基于幅值域参数的船舶液压系统故障诊断研究

针对振动频谱时频域特征信号在船舶液压系统故障诊断领域存在的不足,分析了不同幅值域参数对不同故障存在的敏感度差异,提出了基于幅值域特征分析的多信号、多参数的故障诊断方法,通过5类幅值域无量纲参数和某型船艇装备液压缸4例典型故障对这一方法进行了验证。     

插装阀在立式双孔拉床液压系统中的应用

分析了插装阀在机床液压系统中的应用依据,分析了原拉床液压系统的工作原理,用插装阀设计了立式双孔拉床机床的液压系统,很好地替代了原拉床的液压系统。分析了插装阀工作原理。在拉床液压系统中,采用插装阀具有许多优点,在技术和经济上可行,符合技术发展趋势。     

船舶液压设备故障的成因分析和诊断

本文分析了船舶液压系统设备产生故障的原因,并结合船舶实际情况提出了故障的诊断方法与步骤,可供轮机管理人员参考。     

一种新型船舶舵机系统建模与控制研究

本文对实际舵机系统各个部分进行了数学建模并最终建立了整个舵机系统的模型。通过MATLAB对系统性能进行分析和PID参数设计,提高了系统的响应及信号跟踪性能,对实际系统的设计具有指导意义。     

新型汽车液压增力制动控制器

为了提高汽车制动效率开发一种汽车液压增力制动控制器（HBI）.它主要由增压缸等组成,串联于汽车制动主缸与前制动轮缸之间,将制动主缸输出压力制动液增压,送往前制动轮缸.同时还将压力制动液直接送往后制动轮缸,实现汽车增压制动,其制动效率高于现有减压分配阀组成的制动系统效率10%以上.对具有HBI系统的制动性能检测表明,HBI可用于多种车型的制动系统中,制动踏板力明显下降100 N左右,制动稳定性明显提高.     

Geostress Measurement for Deep-Buried Long Tunnel through Niba Mountain

In the geostress measurement for Niba Mountain on Ya'an-Lugu Expressway, results of Kaiser effect tests combined with focal mechanism solution were compared with those obtained by hydraulic fracturing method, both of which are basically coincident. It is shown that the principal stress increases with burial depth; the maximum principal stress is about 45 MPa, which is larger near fault zones because of stress concentration, and its direction ranges from N20°W to N75°W.     

类比法和引导法在液压传动教学中的探索

在液压传动课程的教学过程中,为了取得良好的教学效果,应着重考虑教学的循序渐进性和因材施教的针对性,以及多种教学方法的并用。文章以一个具体的调速回路为例,分析类比教学法和引导教学法在液压传动教学中的应用。事实证明这两种教学方法在教学中具有明显提升学生学习兴趣,提高专业课程教学效果的意义。