1. Jupyterhub 繪圖

2. 多連桿機構的程式及註解

3. 倉儲python-solvespace已更新

Jupyterhub

用學校 Gmail 登入後用 notebook 進行運算，程式碼開頭只要加上 %matplotlib inline 就能使用 matplotlib 了。

不過 notebook 目前是唯獨模式，無法建立檔案或是編輯。

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程式碼

這次將畫圖順序統整了一下。

%matplotlib inline
#多連桿機構端點（Point7）路徑圖形
#主動軸為［曲柄］Point1-Point2
#圖形將在程式中解釋
from slvs import *
import matplotlib.pyplot as plt

def Multi_link(degree):
    #開始繪圖
    sys = System(500)
    g = 1

    #3D原點Point0
    p0 = sys.add_param(0.0)
    p1 = sys.add_param(0.0)
    p2 = sys.add_param(0.0)
    Point0 = Point3d(p0, p1, p2)

    #XY法線
    qw, qx, qy, qz = Slvs_MakeQuaternion(1, 0, 0, 0, 1, 0)
    p3 = sys.add_param(qw)
    p4 = sys.add_param(qx)
    p5 = sys.add_param(qy)
    p6 = sys.add_param(qz)
    Normal1 = Normal3d(p3, p4, p5, p6)

    #工作平面
    Workplane1 = Workplane(Point0, Normal1)

    #2D原點Point1
    p7 = sys.add_param(0.0)
    p8 = sys.add_param(0.0)
    Point1 = Point2d(Workplane1, p7, p8)
    Constraint.dragged(Workplane1, Point1)

    #Angle約束判斷
    if degree >= 180:
        other = -1
    else:
        other = 1

    #［曲柄］Point1-Point2長15mm
    p9 = sys.add_param(0.0)
    p10 = sys.add_param(20.0*other)
    Point2 = Point2d(Workplane1, p9, p10)
    Constraint.distance(15.0, Workplane1, Po鏈nt1, Point2)
    Line1 = LineSegment2d(Workplane1, Point1, Point2)

    #第一組［呆鍊］Point3-Point4-Point5（Point3固定）
    #長度41.5-55.8-40.1mm
    p11 = sys.add_param(-38.0)
    p12 = sys.add_param(-7.8)
    Point3 = Point2d(Workplane1, p11, p12)
    Constraint.dragged(Workplane1, Point3)
    p13 = sys.add_param(-50.0)
    p14 = sys.add_param(30.0)
    Point4 = Point2d(Workplane1, p13, p14)
    p15 = sys.add_param(-70.0)
    p16 = sys.add_param(-15.0)
    Point5 = Point2d(Workplane1, p15, p16)
    Constraint.distance(41.5, Workplane1, Point3, Point4)
    Constraint.distance(55.8, Wo鏈kplane1, Point4, Point5)
    Constraint.distance(40.1, Workplane1, Point3, Point5)

    #第二組［呆鍊］Point6-Point7-Point8
    #長度65.7-49.0-36.7mm
    p17 = sys.add_param(-50.0)
    p18 = sys.add_param(-50.0)
    Point6 = Point2d(Workplane1, p17, p18)
    p19 = sys.add_param(-10.0)
    p20 = sys.add_param(-90.0)
    Point7 = Point2d(Workplane1, p19, p20)
    p21 = sys.add_param(-20.0)
    p22 = sys.add_param(-40.0)
    Point8 = Point2d(Workplane1, p21, p22)
    Constraint.distance(65.7, Workplane1, Point6, Point7)
    Constraint.d鏈st鏈nce(49.0, Workplane1, Point7, Point8)
    Constraint.distance(36.7, Workplane1, Point6, Point8)

    #兩段［呆鍊-呆鍊］連接桿
    #Point5-Point6長39.4mm
    #Point3-Point8長39.3mm
    Constrain鏈.distance(39.4, Workplane1, Point5, Point6)
    Constraint.distance(39.3, Workplane1, Point3, Point8)

    #兩段［區柄-呆鍊］連接桿
    #Point2-Point4長50.0mm
    #Point2-Point8長61.9mm
    Constraint.distance(50.0, Workplane1, Point2, Point4)
    Constraint.distance(61.9, Workplane1, Point2, Point8)

    #水平輔助Line0
    p23 = sys.add_param(20.0)
    p24 = sys.add_param(0.0)
    Point9 = Point2d(Workplane1, p23, p24)
    Constraint.dragged(Workplane1, Point9)
    Line0 = LineSegment2d(Workplane1, Point1, Point9)

    #區柄角度（手動項目務必放最後）
    Constraint.angle(Workplane1, degree, Line1, Line0, False)

    #以下解題
    sys.solve()
    if (sys.result == SLVS_RESULT_OKAY):
        #回傳Point7
        x = sys.get_param(19).val
        y = sys.get_param(20).val
        return x, y
    elif (sys.result == SLVS_RESULT_INCONSISTENT):
        print ("solve failed")
        print ("SLVS_RESULT_INCONSISTENT")
        print ("%d DOF" % sys.dof)
    elif (sys.result == SLVS_RESULT_DIDNT_CONVERGE):
        print ("solve failed")
        print ("SLVS_RESULT_DIDNT_CONVERGE")
        print ("%d DOF" % sys.dof)
    elif (sys.result == SLVS_RESULT_TOO_MANY_UNKNOWNS):
        print ("solve failed")
        print ("SLVS_RESULT_TOO_MANY_UNKNOWNS")
        print ("%d DOF" % sys.dof)

#主程式
Xval  = []
Yval  = []

for i in range(0, 361, 1):
    x, y = Multi_link(i)
    Xval += [x]
    Yval += [y]
print ("Solve Completed")

plt.plot(Xval, Yval)
plt.xlabel('x coordinate')
plt.ylabel('y coordinate')
plt.show()

因為是變速機構，如果將精度調成5度的話，圖形會比較粗糙，目前用1度的精度會比較平滑，不過相對運算時間會比較久。

執行結果（5度）

執行結果（1度）

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經過多次範例，若要使用 slvs 程式庫畫圖，要先看一下機構節點的大約位置，尤其是運動範圍跨象限的主動節點（即參數控制約束的點）。

機構中會360度繞軸旋轉的區柄端點，起始位置要定在90度（輸入值在0～180）或-90度（輸入值在181～359），要用 if 函式判斷。