伺服阀的参数介绍

SV00 - 3 position 4 port hydraulic servovalve
三位四通液压伺服阀
Description
SV00 is a simple submodel of a 4 ways 3 positions hydraulic
servo-valve.
SV00S是个简单的三位四通液压伺服阀
The spool dynamics is modeled as a 2nd order system with a specified natural frequency and damping ratio.
线轴动力学建模为二阶系统与一个指定的固有频率和阻尼比
For each of the 4 possible flow paths in the central position :
在中位的四个可能的流量路径：
P to A, P to B, T to A and T to B
a flow rate in L/min and a corresponding pressure drop in bar must be specified for the path fully open. Also the critical flow number for transition between laminar and turbulent flow characteristics must be given for each flow path. Normally this dimensionless number can be left at the default value.
流量（L/min）和对应的压降（bar）必须是在阀口全开的情况下。

层流和湍流流动特性临界流数之间的过渡必须给每个流路径。

通常这个无量纲数可以留下作为默认值。

A deadband region can be specified. In this deadband it is assumed that for each flow path there is no flow.
可以指定一个死区。

在这死区假设对于每个流量路径没有流量。

For the two other positions, the flow paths are :
•from P to A and from B to T in the left block
•from P to B and from A to T in the right block
External variables外部参数
Internal variables内部参数
Real parameters真实参数
Integer parameters整体参数
Parameter settings参数设置
The 'index of hydraulic fluid' parameter refers to a fluid type defined by an icon put on the sketch.
液压流体参数指标是指把一个图标在草图上所定义的流体类型。

Sketches and equations草图和方程
With this valve there are 4 flow paths P to A, P to B, T to A and T to B. These are considered to be equivalent to a variable orifices.
The equivalent orifice area areap, areat are computed for each of these paths using the utility eqarea from flow rate / pressure drops pairs. These pairs correspond to the valve being fully open and are normally defined at reference conditions (P 0 = 0 bar, T 0 = 20 C).
But it is possible to use different conditions for density and viscosity by changing the value of the enumeration ( userfp ) and inputing new values for those fluid properties.
这个阀有4个流量路径P到A,P到B、T到A和T到B .这些被认为是相当于一个可变孔。

Areap为等效孔口面积,用这个公式eqarea计算流经这个路径的流量/压降。

这些对阀的压降和流量是在阀口全开的情况下计算的，同样是在参考条件(P 0 = 0bar,T 0 = 20 0C)。

但它也可能有不同的条件通过改变列举密度和粘度的值，并输入新值对于这些流体性质
The input sig is normalized by division by irate and copied to y and modified, if necessary, by the function dlimit so that
输入信号的归一化分工愤怒的，复制到y 或修改后，如有必要，由该函数，以便dlimit
-1 ≤ y ≤ 1
Note that y gives the equilibrium spool position whereas x gives the actual spool position. The second order lag utility sndlag is then used to compute the derivatives of x and v which are xdot and vdot respectively.
注意,y 给平衡线轴位置而x 给实际的线轴的位置。

二阶滞后效用sndlag 然后用于计算导数的x,v,分别xdot 和vdot 。

Note that there are number of distinct possibilities to consider. 请注意,有很多不同的可能性考虑
x ≥ 1
and the valve is saturated at the upper end
是阀饱和的上端
dband ≤ x < 1
and the valve displacement is positive, not
saturated and free of the deadband
和阀位移是积极的,不饱和和自由的死区
-dband ≤ x < dband
and the valve is within the deadband 阀内死区
-1 ≤ x < dband
the valve displacement is negative, not saturated and free of the deadband
这个阀位移为负,不饱和和自由的死区
-1 ≥ x
and the valve is saturated at the lower end
阀是饱和的下端
Rather than call the utility endst2 the code to enforce constraints on the movement of the spool modifying x, xdot, v and vdot if necessary is within the calculation function. After this we have
而不是调用实用程序endst2代码执行约束的运动线轴修改x,v和vdot xdot,必要时在计算函数。

在这之后我们有
-1 ≤ x ≤ 1
Treatment of transition between the modes is treated as a discontinuity but if there is no deadband, no discontinuity is triggered if x goes through the zero position.
1- If x is saturated on the upper end stop, P is connected to A and B to T. The flow rate at port A is calculated using the utility orif3f with orifice area areap . Similarly the flow rate at port T is calculated using the utility orif3f with orifice area areat . The other flow rates are calculated as
如果x是饱和的上端停止,P是连接到A和B 到T .A口流量的计算使用工具与areap orif3f孔口面积。

同样的T口的流量计算使用工具与areat orif3f孔口面积。

其他的流量计算
qp = -qa
qb = -qt
2- For x positive, not saturated and free of the deadband the calculations are as with case 1 but with areas the two areas multiplied by the factor
对于x积极,不饱和和自由的死区,计算与例1但与地区的两个区域乘以系数
3- If x is in the deadband region, all flow rates are zero.
如果x是在死区地区,所有的流量是零
For negative values of x, the method is similar to for cases 1 and 2. 为负值的x,方法类似于例1和2。

For more details concerning the calculation of power for activity analysis in this submodel, please refer to the definitions specific to this library.。