Design and dynamic simulation of hydraulic system of a new automatic transmission

A new hydraulic system of a novel automatic transmission (AT) was designed. The dimension and structure of valves and cylinders were designed by theoretical calculation. The dynamic simulation model of hydraulic system of AT was established by ITI-SimulationX. Simulation results and theoretical design results were compared to confirm the simulation model. Based on the confirmed simulation model, the simulation results of pressure and flow of the hydraulic system were analyzed. The dynamic simulation method is very helpful for designing and analyzing the performance of hydraulic system and further optimization design. The theoretical design method and dynamic simulation model are feasible for the real industrial applications. The research results can be used in hydraulic system design and optimization.

Algorithm of Dynamic Operation Process of Hydraulic Automatically Operated Canals with Constant-Downstream Level Gates

On the basis of analysis the governing process of downstream water level gates AVIO and AVIS, a mathematical model for simulation of dynamic operation process of hydraulically automated irrigation canals instalIed with AVIO and AVIS gates is presented, the main point of this rnathematical model is firstly applying a set of unsteady flow equations （St. Venant equations here） and treating the condition of gate movement as its dynamic boundary, and then deeoupling this interaction of gate movement with the change of canal flow. In this process, it is necessary to give the gateg open-loop transfer function whose input is water level deviation and output is gate discharge. The result of this simulation for a practical reach has shown it has satisfactory accuracy.

Dynamic Simulation and Test Verifcation of Hydraulic Automatic Tensioner for an Engine Timing Chain Drive System

As a fundamental component of an automobile engine’s timing chain drive system, the hydraulic automatic tensioner signifcantly enhances fuel economy while minimizing system vibrations and noise. However, there is a noticeable lack of research on automatic hydraulic tensioners. This study presents a comprehensive calculation approach for the principal parameters of a hydraulic automatic tensioner. An efective method, grounded in hydraulics and multibody dynamics, was introduced for estimating the dynamic response of such a tensioner. The simulation model developed for the hydraulic tensioner is characterized by its rapid dynamic response, consistent operation, and high accuracy. The dynamic behavior of the tensioner was analyzed under varying boundary conditions, using sinusoidal signal excitation. It was observed that the maximum damping force increases with a decreasing leakage gap. Conversely, an increase in oil temperature or air content leads to a decrease in the maximum damping force. The reaction forces derived from these calculations align well with experimental results. This calculation and simulation approach ofers considerable value for the design of innovative hydraulic tensioners. It not only streamlines the design phase, minimizes the number of trials, and reduces product costs, but also provides robust insights for evaluating the performance of hydraulic tensioners.

Analysis on the gear-shifting schedule of hydraulic automatic transmission

With an advanced foreign hydraulic automatic transmission as the objective,an analytical method for the gear-shifting schedule is proposed.First the demanded maximum gradient of test is estimated.Then a test scheme and analytical procedure is formulated by initial test and hypothetical shift parameters.Finally through gear-shifting tests under different road conditions,load,accelerator pedal position limitation,throttle opening and output shaft speed are found to be the gear-shifting parameters.Under a common road condition,the gear-shifting schedule is a double-parameter schedule.Based on the driver＇s demands on braking and dynamic performance,different shift schedules are made under downhill,uphill and quick releasing acceleration pedal conditions.The operation criteria of down-shift schedule on abrupt grade are proposed.

FOUR-PARAMETER AUTOMATIC TRANSMISSION TECHNOLOGY FOR CONSTRUCTION VEHICLE BASED ON ELMAN RECURSIVE NEURAL NETWORK

From the viewpoint of energy saving and improving transmission efficiency, the ZL50E wheel loader is taken as the study object. And the system model is analyzed based on the transmission system of the construction vehicle. A new four-parameter shift schedule is presented, which can keep the torque converter working in the high efficiency area. The control algorithm based on the Elman recursive neural network is applied, and four-parameter control system is developed which is based on industrial computer. The system is used to collect data accurately and control 4D180 power-shift gearbox of ZL50E wheel loader shift timely. An experiment is done on automatic transmission test-bed, and the result indicates that the control system could reliably and safely work and improve the efficiency of hydraulic torque converter. Four-parameter shift strategy that takes into account the power consuming of the working pump has important operating significance and reflects the actual working status of construction vehicle.

Modeling and control for hydraulic transmission of unmanned ground vehicle

Variable pump driving variable motor(VPDVM) is the future development trend of the hydraulic transmission of an unmanned ground vehicle(UGV).VPDVM is a dual-input single-output nonlinear system with coupling,which is difficult to control.High pressure automatic variables bang-bang(HABB) was proposed to achieve the desired motor speed.First,the VPDVM nonlinear mathematic model was introduced,then linearized by feedback linearization theory,and the zero-dynamic stability was proved.The HABB control algorithm was proposed for VPDVM,in which the variable motor was controlled by high pressure automatic variables(HA) and the variable pump was controlled by bang-bang.Finally,simulation of VPDVM controlled by HABB was developed.Simulation results demonstrate the HABB can implement the desired motor speed rapidly and has strong robustness against the variations of desired motor speed,load and pump speed.

基于ADAMS/Hydraulics与Matlab/Simulink的采煤机自动调高系统建模与仿真

为了解决某型号采煤机自动调高系统的可靠性问题,应用Pro/ENGINEER、ANSYS及ADAMS/Hydraulics建立带有液压系统的采煤机刚柔耦合虚拟样机模型。建立控制系统数学模型并应用matlab/simulink仿真软件对建立好的数学模型进行仿真。基于虚拟样机技术的研究,无需制造物理样机就可验证设计结果,为企业的设计研发带来了巨大的经济效益并且能极大地缩短产品研发周期,对于采煤机的设计和研究具有非常重要的意义。

Research on Electro Hydraulic Proportional Control for Heavy Vehicle Blend Braking System

A blend braking system of heavy vehicle was proposed.The main control part of the system is the electro hydraulic proportional servo valve.A nonlinear model of brake cylinder controlled by the valve was deduced through the analysis of its control property and system feature.The transfer function of the system was also proposed,and the hydraulic inherent frequency and the PID closed-loop system feature were calculated.The simulated result is consistent with those tested in the bench and on the site with 50 t heavy vehicle.The experimental result shows that the control method has quick response and high precision.

Improved Design of a Hydraulically Expanded Overhead Cylinder for an Automotive Torsion Beam

The design of hydro-bulge molds,able to provide hollow parts with special-shaped cross-sections,is still a pretty complicated task(especially for what concerns the design of the related hydraulic system and its“synchronization”).In the present work,this task is addressed through the introduction of a new type of overhead cylinder hydraulic synchronization system,able to correct automatically any deviation from the optimal process.Using the AMESim software,the displacement synchronization curve of the piston rods of the two cylinders is obtained and it is verified that the system is able to implement an automatic deviation correction function by adjusting the bidirectional servo valve.A mathematical model for the synchronization system is presented,and the transfer function of the closed-loop control system is determined accordingly.The results show that the system response is generated at about 0.1∼0.2 s with the system reaching an equilibrium state at about 0.2 s.

Automatic lifting system design and application of large load powered support test rig

This paper presented a design of an automatic lifting system. It is used for large load powered support and improves the old method wherein powered support lifting depends on manual control. This system applies a high accuracy gear shunt motor to match the flow for 4 lifting cylinders, and also allocates bypass throttles to realize automatic lifting. Through the dis- placement sensor feedback the height deviation among 4 lifting cylinders during the whole lifting process, when the deviation is up to the sitting value, the corresponding bypass throttle is operated immediately to reduce the deviation, so that the moving platform of the powered support would not be stuck. Through real application, it is shown that this system can realize automatic lifting of powered support; the lifting speed is controlled between 5 and 10 mm/s, and the final aligning accuracy is up to 1 mm.

Hybrid Loader Automatic Shift Strategy Based on Neural Network

Hybrid loader 's comprehensive performance mainly depends on the performance of hydraulic torque converter during its driving and working. Hybrid loader and hydraulic torque converter are taken for the research objects. The primary characteristic curve of hydraulic torque converter and the traction curve of hybrid loader are acquired by analyzing the characteristic parameters of hydraulic torque converter, the characteristic parameters of engine, the characteristic parameters of battery pack and geometric parameters of hybrid loader. The gear shift curves based on the best energy saving performance and the best power performance are acquired respectively with the opening of throttle,the speed of pump wheel and the speed of turbine as parameters. Then the two curves are combined to get the comprehensive gear shift curve. Radical basis function( RBF) neural network is applied to building the gear shift strategy to keep hybrid loader with the best power performance and energy saving performance. The experimental bench is set up for experimental verification. It proves that both of the power performance and energy saving performance of hybrid loader are improved effectively by using the automatic shift strategy.

Based on the PLC technology automation design of on-board pump station oil temperature control system

Vehicle hydraulic pump station, often work environment is poor, the environment temperature difference is very big, the natureof the hydraulic oil is affected by temperature is very big, a lot of damage, PLC automatic control scheme and design of pumping station, the oiltemperature automatic control system realized the automation of the oil temperature control, greatly improving the pump station of the outdoorenvironment to adapt to the performance.

数字孪生下的液压缸机械运行位置自动控制

液压缸机械系统非线性特征复杂,机械运行行为特征不明确,位置控制结果存在偏差,对此,该文提出数字孪生下的液压缸机械运行位置自动控制方法。连续检测液压缸机械系统运行状态,构建非线性状态方程,对比实际测量数据与输出数据的差异,选取RBF核函数与支持向量机,机械运行位置变化量,描述机械运行行为特征,建立位置控制目标函数,将最高适应度值对应的位置点自动更新为副本位置点,引入猫群算法求解目标函数,对位置控制目标函数的全局最优解展开更新,实现液压缸机械运行位置自动控制。实验结果表明,所提方法应用后,位移检测曲线与实际位移曲线之间的偏差较小,且在恒负载工况下和变负载工况下,位移稳态误差均较小,说明其机械运行位置自动控制结果精度高、控制效率高、控制精度高。

基于高阶滑模算法的飞机架水平控制方法研究

为提高飞机架水平操作过程的自动化水平,该文针对运八飞机在飞行试验过程中所需的飞机架水平操作系统进行设计研究,提出一种基于高阶滑模算法的运八飞机架水平控制及实现方法。该方法基于三点调平机构,在对系统硬件进行设计的基础上,分别对系统支撑装置、驱动电机、电动泵以及千斤顶进行数学建模分析,并基于高阶滑模算法对控制系统以及滑模控制器进行设计。搭建试验平台进行验证,试验结果表明:飞机各支点位置误差在0.5 mm以内,实际运行测试结果与仿真结果误差较小,误差仅为1.9%。该系统能够实现预期目标,调平精度满足技术要求,可为飞机架水平操作提供一种新的发展方向。

一种带自反馈的搬运车液压控制装置设计

针对普通液压搬运车人工操作时受力无法控制且不能适应任意高度的问题,该文在传统液压搬运车的基础上进行了改造,设计加装了一套以信息采集、传输、处理、分析和反馈为闭环的自动控制装置。通过传感器收集载荷和位置等数据信息,再利用PID数字处理算法对信息加以分析,确认相关参数,从而实现了搬运车在自动控制下的平稳运行。同时,还根据载荷和高度位置的不同进行自适应调节反馈,使其在最短的时间内稳定地达到设计效果。实验测试分析结果表明,加装所提自动控制装置的搬运车相比于传统的人工操作方法,节省时间约40%,且该设计能够适用于多种复杂的搬运场景,具有良好的工程普适性。

矿用自动液压锚杆钻机可靠性分配研究

针对自动液压锚杆钻机可靠性数据缺乏、结构复杂、工作环境恶劣的问题,优选了代数分配法作为其可靠性分配方法。通过结构功能分析,将钻机划分为8个组元并建立了可靠性分析模型。依据MT/T 688-1997《煤矿用锚杆钻机通用技术条件》计算了钻机故障率。运用代数分配法完成了钻机可靠性分配,研究结果表明控制系统等4个组元为薄弱环节。从提升关键部件可靠性和钻机加载试验两方面提出了钻机可靠性提升建议,对于自动液压锚杆钻机研发具有参考价值。

残膜回收机自动仿形系统设计与试验

目前残膜回收机已经成为新疆棉田回收残膜的主要方式之一。在残膜回收机回收残膜的过程中,由于棉田的环境复杂多变,而现有的残膜回收机无仿形功能,导致入土部件的入土深度不稳定,这就造成残膜拾净率达不到预期结果等问题。4JSM-2.1A型棉秸秆还田及残膜回收联合作业机存在同样问题,所以根据此机型设计一套机-电-液配合的自动仿形系统,对地面仿形传感机构的运动进行分析,确定机械部件的关键参数,并对仿形系统进行场地试验和田间试验。结果表明,该机工作稳定可靠,整体仿形稳定,在机具作业速度为6.5~7 km/h时,其入土部件的入土深度平均值为91.6 mm,其标准差为3.13 mm,残膜拾净率达89.5%。

重型液力自动变速器行星排非线性动力学分析

建立了重型液力自动变速器在某挡位下行星齿轮传动系统的非线性纯扭转动力学模型,该挡位工作模式充分体现了行星排之间的复合关系,该动力学模型综合考虑了时变啮合刚度、齿侧间隙与啮合误差幅值等系统内部激励因素,在此基础上推导出系统在广义坐标下的无量纲动力学方程。采用4阶龙格-库塔法对非线性微分方程组进行求解,得到了系统的非线性动态响应。综合运用时域响应、频域响应、相平面图、系统分岔和Poincare截面研究了具体的输入转速与系统响应的关系,得出了该挡位下的合理转速。研究了复合结构导致的各级行星排之间的响应差异,发现单个行星排可以影响甚至决定整个传动系统的响应,可以此为根据指导生产制造,降低生产成本。

智能型多功能油液监测分离控制技术研究应用

针对冶金行业中,特别是热轧企业较为恶劣的工作环境,液压、润滑系统极易进水并发生油液乳化的问题,提出了智能型多功能油液监测分离控制技术,并介绍了该技术的装置和原理。基于试用情况,通过采取调整循环过滤泵参数、优化循环过滤泵工作时间和加热温度、优化装置安装位置、安装分离滤芯和手动排除杂质等措施,有效解决了液压、润滑系统油液乳化问题,减少了液压冲击和系统泄漏现象,年均节约成本约530.56万元。

自动垂直钻井工具纠斜液压系统的研究

对一种用于石油自动垂直钻井工具的纠斜液压系统展开研究,以实现钻具的纠斜力稳定、可变及钻具矢量纠斜效果。针对油缸压力无法调节及液压泵引起油缸压力不易稳定的问题,研究一种新型纠斜液压系统。在建立纠斜液压系统数学模型的基础上,进行了系统和油缸压力的动态响应分析。仿真结果表明,新型纠斜液压系统提供的导向推力较传统系统稳定性更高,压力波动幅度更低;调节比例溢流阀的输入电流55~85 mA,并保持比例溢流阀输入电流增量不变,钻杆转速越大,油缸压力在单位时间内的开环调节精度就越高。