步进电机控制系统外文翻译

1、步进电机的振荡、不稳定以及控制摘要：本文介绍了一种分析永磁步进电机不稳定性的新颖方法。结果表明，该种电机有两种类型的不稳定现象：中频振荡和高频不稳定性。非线性分叉理论是用来说明局部不稳定和中频振荡运动之间的关系。一种新型的分析介绍了被确定为高频不稳定性的同步损耗现象。在相间分界线和吸引子的概念被用于导出数量来评估高频不稳定性。通过使用这个数量就可以很容易地估计高频供应的稳定性。此外，还介绍了稳定性理论。广义的方法给出了基于反馈理论的稳定问题的分析。结果表明，中频稳定度和高频稳定度可以提高状态反馈。关键词：步进电机，不稳定，非线性，状态反馈。1. 介绍步进电机是将数字脉冲输入转换为模拟角度输出的

2、电磁增量运动装置。其内在的步进能力允许没有反馈的精确位置控制。 也就是说，他们可以在开环模式下跟踪任何步阶位置，因此执行位置控制是不需要任何反馈的。步进电机提供比直流电机每单位更高的峰值扭矩;此外，它们是无电刷电机，因此需要较少的维护。所有这些特性使得步进电机在许多位置和速度控制系统的选择中非常具有吸引力，例如如在计算机硬盘驱动器和打印机，代理表，机器人中的应用等.尽管步进电机有许多突出的特性，他们仍遭受振荡或不稳定现象。这种现象严重地限制其开环的动态性能和需要高速运作的适用领域。 这种振荡通常在步进率低于1000脉冲/秒的时候发生，并已被确认为中频不稳定或局部不稳定1，或者动态不稳定2。此外

3、，步进电机还有另一种不稳定现象，也就是在步进率较高时，即使负荷扭矩小于其牵出扭矩，电动机也常常不同步。该文中将这种现象确定为高频不稳定性，因为它以比在中频振荡现象中发生的频率更高的频率出现。高频不稳定性不像中频不稳定性那样被广泛接受，而且还没有一个方法来评估它。中频振荡已经被广泛地认识了很长一段时间，但是，一个完整的了解还没有牢固确立。这可以归因于支配振荡现象的非线性是相当困难处理的。大多数研究人员在线性模型基础上分析它1。尽管在许多情况下，这种处理方法是有效的或有益的，但为了更好地描述这一复杂的现象，在非线性理论基础上的处理方法也是需要的。例如，基于线性模型只能看到电动机在某些供应频率下转向

4、局部不稳定，并不能使被观测的振荡现象更多深入。事实上，除非有人利用非线性理论，否则振荡不能评估。因此，在非线性动力学上利用被发展的数学理论处理振荡或不稳定是很重要的。值得指出的是，Taft和Gauthier3，还有Taft和Harned4使用的诸如在振荡和不稳定现象的分析中的极限环和分界线之类的数学概念，并取得了关于所谓非同步现象的一些非常有启发性的见解。尽管如此，在这项研究中仍然缺乏一个全面的数学分析。本文一种新的数学分被开发了用于分析步进电机的振动和不稳定性。本文的第一部分讨论了步进电机的稳定性分析。结果表明，中频振荡可定性为一种非线性系统的分叉现象（霍普夫分叉）。本文的贡献之一是将中频振

5、荡与霍普夫分叉联系起来，从而霍普夫理论从理论上证明了振荡的存在性。高频不稳定性也被详细讨论了，并介绍了一种新型的量来评估高频稳定。这个量是很容易计算的，而且可以作为一种标准来预测高频不稳定性的发生。在一个真实电动机上的实验结果显示了该分析工具的有效性。本文的第二部分通过反馈讨论了步进电机的稳定性控制。一些设计者已表明，通过调节供应频率 5 ，中频不稳定性可以得到改善。特别是Pickup和Russell 6，7都在频率调制的方法上提出了详细的分析。在他们的分析中，雅可比级数用于解决常微分方程和一组数值有待解决的非线性代数方程组。此外，他们的分析负责的是双相电动机，因此，他们的结论不能直接适用于我

6、们需要考虑三相电动机的情况。在这里，我们提供一个没有必要处理任何复杂数学的更简洁的稳定步进电机的分析。在这种分析中，使用的是d-q模型的步进电机。由于双相电动机和三相电动机具有相同的d-q模型，因此，这种分析对双相电动机和三相电动机都有效。迄今为止，人们仅仅认识到用调制方法来抑制中频振荡。本文结果表明，该方法不仅对改善中频稳定性有效，而且对改善高频稳定性也有效。2. 动态模型的步进电机本文件中所考虑的步进电机由一个双相或三相绕组的跳动定子和永磁转子组成。一个极对三相电动机的简化原理如图1所示。步进电机通常是由被脉冲序列控制产生矩形波电压的电压源型逆变器供给的。这种电动机用本质上和同步电动机相同

7、的原则进行作业。步进电机主要作业方式之一是保持提供电压的恒定以及脉冲频率在非常广泛的范围上变化。在这样的操作条件下，振动和不稳定的问题通常会出现。图1.三相电动机的图解模型 用qd框架参考转换建立了一个三相步进电机的数学模型 。下面给出了三相绕组电压方程va = Ria + L*dia /dt M*dib/dt M*dic/dt + dpma/dt ,vb = Rib + L*dib/dt M*dia/dt M*dic/dt + dpmb/dt ,vc = Ric + L*dic/dt M*dia/dt M*dib/dt + dpmc/dt , (1) 其中R和L分别是相绕组的电阻和感应线圈，

8、并且M是相绕组之间的互感线圈。pma, pmb and pmc 是应归于永磁体 的相的磁通，且可以假定为转子位置的正弦函数如下pma = 1 sin(N),pmb = 1 sin(N 2 QUOTE /3),pmc = 1 sin(N - 2 QUOTE /3), (2)其中N是转子齿数。本文中强调的非线性由上述方程所代表，即磁通是转子位置的非线性函数。使用Q ,d转换，将参考框架由固定相轴变换成随转子移动的轴（参见图2）。矩阵从a,b,c框架转换成q,d框架变换被给出了8 (3)例如，给出了q,d参考里的电压 (4)在a,b,c参考中，只有两个变量是独立的（ia + ib + ic = 0）

9、，因此，上面提到的由三个变量转化为两个变量是允许的。在电压方程（1）中应用上述转换，在q,d框架中获得转换后的电压方程为vq = Riq + L1*diq/dt + NL1id + N1,vd = Rid + L1*did/dt NL1iq, (5) 图2，a,b,c和d,q参考框架其中L1 = L + M，且是电动机的速度。有证据表明,电动机的扭矩有以下公式T = 3/2N1iq . (6)转子电动机的方程为J*d/dt = 3/2*N1iq Bf Tl , (7) 如果Bf是粘性摩擦系数，和Tl代表负荷扭矩（在本文中假定为恒定）。为了构成完整的电动机的状态方程，我们需要另一种代表转子位置的

10、状态变量。为此，通常使用满足下列方程的所谓的负荷角8D/dt = 0 , (8) 其中0是电动机的稳态转速。方程（5），（7），和（8）构成电动机的状态空间模型，其输入变量是电压vq和vd.如前所述，步进电机由逆变器供给，其输出电压不是正弦电波而是方波。然而，由于相比正弦情况下非正弦电压不能很大程度地改变振荡特性和不稳定性（如将在第3部分显示的，振荡是由于电动机的非线性），为了本文的目的我们可以假设供给电压是正弦波。根据这一假设，我们可以得到如下的vq和vdvq = Vmcos(N) ,vd = Vmsin(N) , (9) 其中Vm是正弦波的最大值。上述方程，我们已经将输入电压由时间函数转变

11、为状态函数，并且以这种方式我们可以用自控系统描绘出电动机的动态，如下所示。这将有助于简化数学分析。根据方程（5），（7），和（8），电动机的状态空间模型可以如下写成矩阵式 = F(X,u) = AX + Fn(X) + Bu , (10) 其中X = iq id T, u = 1 Tl T 定义为输入，且1 = N0 是供应频率。输入矩阵B被定义为矩阵A是F(.)的线性部分，如下Fn(X)代表了F(.)的线性部分，如下输入端u独立于时间，因此，方程（10）是独立的。在F(X,u)中有三个参数，它们是供应频率1，电源电压幅度Vm和负荷扭矩Tl。这些参数影响步进电机的运行情况。在实践中，通常用这样

12、一种方式来驱动步进电机，即用因指令脉冲而变化的供应频率1来控制电动机的速度，而电源电压保持不变。因此，我们应研究参数1的影响。3.分叉和中频振荡，设=0，得出方程（10）的平衡且是它的相角， = arctan(1L1/R) . (16) 方程（12）和（13）显示存在着多重均衡，这意味着这些平衡永远不能全局稳定。人们可以看到，如方程（12）和（13）所示有两组平衡。第一组由方程（12）对应电动机的实际运行情况来代表。第二组由方程（13）总是不稳定且不涉及到实际运作情况来代表。在下面，我们将集中精力在由方程（12）代表的平衡上。 附件2：外文原文 Oscillation, Instability

13、 and Control of Stepper MotorsLIYU CAO and HOWARD M. SCHWARTZDepartment of Systems and Computer Engineering, Carleton University, 1125 Colonel By Drive,Ottawa, ON K1S 5B6, Canada(Received: 18 February 1998; accepted: 1 December 1998)Abstract. A novel approach to analyzing instability in permanent-ma

14、gnet stepper motors is presented. It is shown that there are two kinds of unstable phenomena in this kind ofmotor: mid-frequency oscillation and high-frequency instability. Nonlinear bifurcation theory is used to illustrate the relationship between local instability and midfrequencyoscillatory motio

15、n. A novel analysis is presented to analyze the loss of synchronism phenomenon, which is identified as high-frequency instability. The concepts of separatrices and attractors in phase-space are used to derive a quantity to evaluate the high-frequency instability. By using this quantity one can easil

16、y estimate the stability for high supply frequencies. Furthermore, a stabilization method is presented. A generalized approach to analyze the stabilization problem based on feedback theory is given. It is shown that the mid-frequency stabilityand the high-frequency stability can be improved by state

17、 feedback. Keywords: Stepper motors, instability, nonlinearity, state feedback.1. IntroductionStepper motors are electromagnetic incremental-motion devices which convert digital pulse inputs to analog angle outputs. Their inherent stepping ability allows for accurate position control without feedbac

18、k. That is, they can track any step position in open-loop mode, consequently no feedback is needed to implement position control. Stepper motors deliver higher peak torque per unit weight than DC motors; in addition, they are brushless machines and therefore require less maintenance. All of these pr

19、operties have made stepper motors a very attractive selection in many position and speed control systems, such as in computer hard disk drivers and printers, XY-tables, robot manipulators, etc.Although stepper motors have many salient properties, they suffer from an oscillation or unstable phenomeno

20、n. This phenomenon severely restricts their open-loop dynamic performance and applicable area where high speed operation is needed. The oscillation usually occurs at stepping rates lower than 1000 pulse/s, and has been recognized as a mid-frequency instability or local instability 1, or a dynamic in

21、stability 2. In addition, there is another kind of unstable phenomenon in stepper motors, that is, the motors usually lose synchronism at higher stepping rates, even though load torque is less than their pull-out torque. This phenomenon is identified as high-frequency instability in this paper, beca

22、use it appears at much higher frequencies than the frequencies at which the mid-frequency oscillation occurs. The high-frequency instability has not been recognized as widely as mid-frequency instability, and there is not yet a method to evaluate it.Mid-frequency oscillation has been recognized wide

23、ly for a very long time, however, a complete understanding of it has not been well established. This can be attributed to the nonlinearity that dominates the oscillation phenomenon and is quite difficult to deal with.384 L. Cao and H. M. SchwartzMost researchers have analyzed it based on a linearize

24、d model 1. Although in many cases, this kind of treatments is valid or useful, a treatment based on nonlinear theory is needed in order to give a better description on this complex phenomenon. For example, based on a linearized model one can only see that the motors turn to be locally unstable at so

25、me supplyfrequencies, which does not give much insight into the observed oscillatory phenomenon. In fact, the oscillation cannot be assessed unless one uses nonlinear theory.Therefore, it is significant to use developed mathematical theory on nonlinear dynamics to handle the oscillation or instabili

26、ty. It is worth noting that Taft and Gauthier 3, and Taft and Harned 4 used mathematical concepts such as limit cycles and separatrices in the analysis of oscillatory and unstable phenomena, and obtained some very instructive insights into the socalled loss of synchronous phenomenon. Nevertheless, t

27、here is still a lack of a comprehensive mathematical analysis in this kind of studies. In this paper a novel mathematical analysis is developed to analyze the oscillations and instability in stepper motors.The first part of this paper discusses the stability analysis of stepper motors. It is shown t

28、hat the mid-frequency oscillation can be characterized as a bifurcation phenomenon (Hopf bifurcation) of nonlinear systems. One of contributions of this paper is to relate the midfrequency oscillation to Hopf bifurcation, thereby, the existence of the oscillation is provedtheoretically by Hopf theor

29、y. High-frequency instability is also discussed in detail, and a novel quantity is introduced to evaluate high-frequency stability. This quantity is very easyto calculate, and can be used as a criteria to predict the onset of the high-frequency instability. Experimental results on a real motor show

30、the efficiency of this analytical tool.The second part of this paper discusses stabilizing control of stepper motors through feedback. Several authors have shown that by modulating the supply frequency 5, the midfrequencyinstability can be improved. In particular, Pickup and Russell 6, 7 have presen

31、ted a detailed analysis on the frequency modulation method. In their analysis, Jacobi series was used to solve a ordinary differential equation, and a set of nonlinear algebraic equations had to be solved numerically. In addition, their analysis is undertaken for a two-phase motor, and therefore, th

32、eir conclusions cannot applied directly to our situation, where a three-phase motor will be considered. Here, we give a more elegant analysis for stabilizing stepper motors, where no complex mathematical manipulation is needed. In this analysis, a dq model of stepper motors is used. Because two-phas

33、e motors and three-phase motors have the same qd model and therefore, the analysis is valid for both two-phase and three-phase motors. Up to date, it is only recognized that the modulation method is needed to suppress the midfrequency oscillation. In this paper, it is shown that this method is not o

34、nly valid to improve mid-frequency stability, but also effective to improve high-frequency stability.2. Dynamic Model of Stepper MotorsThe stepper motor considered in this paper consists of a salient stator with two-phase or threephase windings, and a permanent-magnet rotor. A simplified schematic o

35、f a three-phase motor with one pole-pair is shown in Figure 1. The stepper motor is usually fed by a voltage-source inverter, which is controlled by a sequence of pulses and produces square-wave voltages. Thismotor operates essentially on the same principle as that of synchronous motors. One of majo

36、r operating manner for stepper motors is that supplying voltage is kept constant and frequencyof pulses is changed at a very wide range. Under this operating condition, oscillation and instability problems usually arise.Figure 1. Schematic model of a three-phase stepper motor.A mathematical model fo

37、r a three-phase stepper motor is established using qd framereference transformation. The voltage equations for three-phase windings are given byva = Ria + L*dia /dt M*dib/dt M*dic/dt + dpma/dt ,vb = Rib + L*dib/dt M*dia/dt M*dic/dt + dpmb/dt ,vc = Ric + L*dic/dt M*dia/dt M*dib/dt + dpmc/dt ,where R

38、and L are the resistance and inductance of the phase windings, and M is the mutual inductance between the phase windings. _pma, _pmb and _pmc are the flux-linkages of thephases due to the permanent magnet, and can be assumed to be sinusoid functions of rotor position _ as followpma = 1 sin(N),pmb =

39、1 sin(N 2 QUOTE /3),pmc = 1 sin(N - 2 QUOTE /3),where N is number of rotor teeth. The nonlinearity emphasized in this paper is represented by the above equations, that is, the flux-linkages are nonlinear functions of the rotor position.By using the q; d transformation, the frame of reference is chan

40、ged from the fixed phase axes to the axes moving with the rotor (refer to Figure 2). Transformation matrix from the a; b; c frame to the q; d frame is given by 8For example, voltages in the q; d reference are given byIn the a; b; c reference, only two variables are independent (ia C ib C ic D 0); th

41、erefore, the above transformation from three variables to two variables is allowable. Applying the abovetransformation to the voltage equations (1), the transferred voltage equation in the q; d frame can be obtained asvq = Riq + L1*diq/dt + NL1id + N1,vd=Rid + L1*did/dt NL1iq, (5)Figure 2. a, b, c a

42、nd d, q reference frame.where L1 D L CM, and ! is the speed of the rotor.It can be shown that the motors torque has the following form 2T = 3/2N1iqThe equation of motion of the rotor is written asJ*d/dt = 3/2*N1iq Bf Tl ,where Bf is the coefficient of viscous friction, and Tl represents load torque,

43、 which is assumed to be a constant in this paper.In order to constitute the complete state equation of the motor, we need another state variable that represents the position of the rotor. For this purpose the so called load angle _ 8 is usually used, which satisfies the following equationD/dt = 0 ,w

44、here !0 is steady-state speed of the motor. Equations (5), (7), and (8) constitute the statespace model of the motor, for which the input variables are the voltages vq and vd. As mentioned before, stepper motors are fed by an inverter, whose output voltages are not sinusoidal but instead are square

45、waves. However, because the non-sinusoidal voltages do not change the oscillation feature and instability very much if compared to the sinusoidal case (as will be shown in Section 3, the oscillation is due to the nonlinearity of the motor), for the purposes of this paper we can assume the supply vol

46、tages are sinusoidal. Under this assumption, we can get vq and vd as followsvq = Vmcos(N) ,vd = Vmsin(N) ,where Vm is the maximum of the sine wave. With the above equation, we have changed the input voltages from a function of time to a function of state, and in this way we can represent the dynamic

47、s of the motor by a autonomous system, as shown below. This will simplify the mathematical analysis.From Equations (5), (7), and (8), the state-space model of the motor can be written in a matrix form as follows = F(X,u) = AX + Fn(X) + Bu , (10)where X D Tiq id ! _UT , u D T!1 TlUT is defined as the

48、 input, and !1 D N!0 is the supply frequency. The input matrix B is defined byThe matrix A is the linear part of F._/, and is given byFn.X/ represents the nonlinear part of F._/, and is given byThe input term u is independent of time, and therefore Equation (10) is autonomous.There are three paramet

49、ers in F.X;u/, they are the supply frequency !1, the supply voltage magnitude Vm and the load torque Tl . These parameters govern the behaviour of the stepper motor. In practice, stepper motors are usually driven in such a way that the supply frequency !1 is changed by the command pulse to control t

50、he motors speed, while the supply voltage is kept constant. Therefore, we shall investigate the effect of parameter !1.3. Bifurcation and Mid-Frequency OscillationBy setting ! D !0, the equilibria of Equation (10) are given asand is its phase angle defined by = arctan(1L1/R) . (16) Equations (12) an

51、d (13) indicate that multiple equilibria exist, which means that these equilibria can never be globally stable. One can see that there are two groups of equilibria as shown in Equations (12) and (13). The first group represented by Equation (12) corresponds to the real operating conditions of the mo

52、tor. The second group represented by Equation (13) is always unstable and does not relate to the real operating conditions. In the following, we will concentrate on the equilibria represented by Equation (12).附录资料：不需要的可以自行删除地下连续墙施工工艺标准1、范围本工艺适用于工业与民用建筑地下连续墙基坑工程。地下连续墙是在地面上采用一种挖槽机械，沿着深开挖工程的周边轴线，在泥浆护壁条

53、件下，开挖出一条狭长的深槽，清槽后，在槽内吊放钢筋笼，然后用导管法灌筑水下混凝土筑成一个单元槽段，如此逐段进行，在地下筑成一道连续的钢筋混凝土墙壁，作为截水、防渗、承重、挡水结构。本法特点是：施工振动小，墙体刚度大，整体性好，施工速度快，可省土石方，可用于密集建筑群中建造深基坑支护及进行逆作法施工，可用于各种地质条件下，包括砂性土层、粒径50mm以下的砂砾层中施工等。适用于建造建筑物的地下室、地下商场、停车场、地下油库、挡土墙、高层建筑的深基础、逆作法施工围护结构，工业建筑的深池、坑；竖井等。2、施工准备2.1材料要求2.1.1水泥用32.5号或42.5号普通硅酸盐水泥或矿渣硅酸盐水泥，要求新

54、鲜无结块。2.1.2砂宜用粒度良好的中、粗砂，含泥量小于5%。2.1.3石子宜采用卵石，如使用碎石，应适当增加水泥用量及砂率，以保证坍落度及和易性的要求。其最大粒径不应大于导管内径的16和钢筋最小间距的14，且不大于40mm。含泥量小于2%。2.1.4外加剂可根据需要掺加减水剂、缓凝剂等外加剂，掺入量应通过试验确定。2.1.5钢筋按设计要求选用，应有出厂质量证明书或试验报告单，并应取试样作机械性能试验，合格后方可使用。2.1.6泥浆材料泥浆系由土料、水和掺合物组成。拌制泥浆使用膨润土，细度应为200250目，膨润率510倍，使用前应取样进行泥浆配合比试验。如采取粘土制浆时，应进行物理、化学分析

55、和矿物鉴定，其粘粒含量应大于50%，塑性指数大于20，含砂量小于5%，二氧化硅与三氧化铝含量的比值宜为34。掺合物有分散剂、增粘剂(CMC)等。外加剂的选择和配方需经试验确定，制备泥浆用水应不含杂质，pH值为79。2.2主要机具设备2.2.1成槽设备有多头钻成槽机、抓斗式成槽机、冲击钻、砂泵或空气吸泥机(包括空压机)、轨道转盘等2.2.2混凝土浇灌机具有混凝土搅拌机、浇灌架(包括储料斗、吊车或卷扬机)、金属导管和运输设备等。2.2.3制浆机具有泥浆搅拌机、泥浆泵、空压机、水泵、软轴搅拌器、旋流器、振动筛、泥浆比重秤、漏斗粘度计、秒表、量筒或量杯、失水量仪、静切力计、含砂量测定器、pH试纸等。2

56、.2.4槽段接头设备有金属接头管、履带或轮胎式起重机、顶升架(包括支承架、大行程千斤顶和油泵等)或振动拔管机等。2.2.5其他机具设备有钢筋对焊机，弯曲机，切断机，交、直流电焊机，大、小平锹，各种扳手等。2.3作业条件、2.3.1在工程范围内钻探，查明地质、地层、土质以及水文情况，为选择挖槽机具、泥浆循环工艺、槽段长度等提供可靠的技术数据.。同时进行钻探，摸清地下连续墙部位的地下障碍物情况。2.3.2按设计地面标高进行场地平整，拆迁施工区域内的房屋、通讯、电力设施以及上下水管道等障碍物，挖除工程部位地面以下m内的地下障碍物。施工场地周围设置排水系统。2.3.3根据工程结构、地质情况及施工条件制

57、定施工方案，选定并准备机具设备，进行施工部署、平面规划、劳动配备及划分槽段；确定泥浆配合比、配制及处理方法，编制材料、施工机具需用量计划及技术培训计划，提出保证质量、安全及节约等的技术措施。2.3.4按平面及工艺要求设置临时设施，修筑道路，在施工区域设置导墙；安装挖槽、泥浆制配、处理、钢筋加工机具设备；安装水电线路；进行试通水、通电、试运转、试挖槽、混凝土试浇灌。3、操作工艺3.1工艺流程(图3.1)图3.1多头钻施工及泥浆循环工艺3.2导墙设置3.2.1在槽段开挖前，沿连续墙纵向轴线位置构筑导墙，采用现浇混凝土或钢筋混凝土浇3.2.2导墙深度一般为12m，其顶面略高于地面50100mm，以防

58、止地表水流入导沟。导墙的厚度一般为100200mm，内墙面应垂直，内壁净距应为连续墙设计厚度加施工余量(一般为4060mm)。墙面与纵轴线距离的允许偏差为10mm，内外导墙间距允许偏盖5mm，导墙顶面应保持水平。3.2.3导墙宜筑于密实的粘性土地基上。墙背宜以土壁代模，以防止槽外地表水渗入槽内。如果墙背侧需回填土时，应用粘性土分层夯实，以免漏浆。每个槽段内的导墙应设一溢浆孔。3.2.4导墙顶面应高出地下水位1m以上，以保证槽内泥浆液面高于地下水位0.5m以上，且不低于导墙顶面0.3m。3.2.5导墙混凝土强度应达到70%以上方可拆模。拆模后，应立即将导墙间加木支撑至槽段开挖拆除。严禁重型机械通

59、过、停置或作业，以防导墙开裂或变形。3.3泥浆制备和使用3.3.1泥浆的性能和技术指标，应根据成槽方法和地质情况而定，一般可按表3.3.1采用。泥浆性能指标表3.3.1项目性能指标检查方法一般地层软弱土层密度粘度胶体率稳定性失水量pH值泥皮厚度静切力(1min)含砂量1.041.25kgL1822s95%0.05gcm330mL30min101.53.0mm30min1020mgcm298%0.02gcm320mL30min891.01.5mm30min2050mgcm24%泥浆密度秤500700mL漏斗法100mL量杯法500mL量筒或稳定计失水量仪pH试纸失水量仪静切力计含砂量测定器注：1

60、.密度：表中上限为新制泥浆，下限为循环泥浆。一般采用膨润土泥浆时，新浆密度控制在1.041.05；循环程中的泥浆控制在1.251.30；对于松散易坍地层，密度可适当加大。浇灌混凝土前槽内泥浆控制在1.151.25，视土质情况而定；2.成槽时，泥浆主要起护壁作用，在一般情况下可只考虑密度、粘度、胶体率三项指标；3.当存在易塌方土层(如砂层或地下水位下的粉砂层等)或采用产生冲击、冲刷的掘削机械时，应适当考虑，泥浆粘度，宜用2530s。3.3.2在施工过程中应加强检查和控制泥浆的性能，定时对泥浆性能进行测试，随时调泥浆配合比，做好泥浆质量检测记录。一般作法是：在新浆拌制后静止24h，测一次全项(含砂