This article presents a quasistatic model of a hydraulic actuator driven by a four-valve independent metering circuit. The presented model describes the quasistatic balance between the velocity and force and that between the flowrate and the pressure. In such balanced states, the pressure difference across each valve determines the oil flowrate through the valve, the oil flowrate into the actuator determines the velocity of the actuator, and the pressures in the actuator chambers are algebraically related to the external force acting on the actuator. Based on these relations, we derive a set of quasistatic representations, which analytically relates the control valve openings, the actuator velocity, and the external force. This analytical expression is written with nonsmooth functions, of which the return values are set-valued instead of single-valued. We also show a method of incorporating the obtained nonsmooth quasistatic model into multibody simulators, in which a virtual viscoelastic element is used to mimic transient responses. In addition, the proposed model is extended to include a regeneration pipeline and to deal with a collection of actuators driven by a single pump.

中文翻译：

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液压执行器的非光滑拟静力学建模

本文介绍了由四阀独立计量回路驱动的液压执行器的准静态模型。提出的模型描述了速度和力之间以及流量和压力之间的准静态平衡。在这种平衡状态下，每个阀上的压差确定通过阀的油流量，进入执行机构的油流量确定执行机构的速度，执行机构腔中的压力与作用在执行机构上的外力代数相关。基于这些关系，我们得出了一组准静态表示形式，这些解析形式将控制阀的开度，执行器速度和外力关联起来。这个解析表达式是用非平滑函数编写的，其中的返回值是设置值而不是单值。我们还展示了一种将获得的非光滑拟静态模型合并到多体仿真器中的方法，其中使用虚拟粘弹性元件模拟瞬态响应。另外，所提出的模型被扩展为包括再生管道并处理由单个泵驱动的致动器的集合。