chrono.ChCoordsysD(chrono.ChVectorD(0, 0, -1),
chrono.Q_from_AngY(chrono.CH_C_PI_2)))
system.AddLink(prismatic1)
prismatic2 = chrono.ChLinkLockPrismatic()
prismatic2.Initialize(
slider2, ground,
chrono.ChCoordsysD(chrono.ChVectorD(0, 0, 1),
chrono.Q_from_AngY(chrono.CH_C_PI_2)))
system.AddLink(prismatic2)
# Sine function parameters
freq = 1
ampl = 4
omg = 2 * chrono.CH_C_PI * freq
mod = chrono.ChFunction_Sine(0, freq, ampl)
# Actuate first slider using a link force
prismatic1.GetForce_Z().SetActive(True)
prismatic1.GetForce_Z().SetF(1)
prismatic1.GetForce_Z().SetModulationF(mod)
# Actuate second slider using a body force
frc2 = chrono.ChForce()
frc2.SetF_x(mod)
slider2.AddForce(frc2)
# Create the Irrlicht application
application = irr.ChIrrApp(system, "Actuated prismatic joint",
irr.dimension2du(800, 600), False, True)
application.AddTypicalLogo()
my_shbodyA.SetName('BodyA')
my_shbodyA.SetInertiaXX( chrono.ChVectorD(10,10,10) )
print (my_shbodyA.GetInertia() )
my_shbodyA.SetPos(chrono.ChVectorD(1,-1,0))
my_shbodyA.GetCollisionModel().AddBox(10,1,10)
my_shbodyA.SetBodyFixed(True)
my_shbodyA.SetCollide(True)
my_shbodyB = chrono.ChBody()
my_shbodyB.SetName('BodyB')
my_shbodyB.SetPos(chrono.ChVectorD(0,2,0))
my_shbodyB.GetCollisionModel().AddBox(1,1,1)
my_shbodyB.SetCollide(True)
my_shmarker = chrono.ChMarker()
my_funct = chrono.ChFunction_Sine(0,0.5,3)
my_shmarker.SetMotion_X(my_funct)
my_shmarker.SetPos(chrono.ChVectorD(1,2,3))
my_shbodyB.AddMarker(my_shmarker)
my_system.Add(my_shbodyA)
my_system.Add(my_shbodyB)
# Define surface material(s)
my_shmaterial = chrono.ChMaterialSurfaceNSC()
my_shmaterial.SetFriction(0.3)
my_shmaterial.SetCompliance(0)
my_shbodyA.SetMaterialSurface(my_shmaterial)
my_shbodyB.SetMaterialSurface(my_shmaterial)
if not my_floor :
sys.exit('Error: cannot find floor from its name in the C::E system!')
my_floor.AddAsset(floor_povmat)
my_ground = my_system.SearchBody('ground')
if not my_ground :
sys.exit('Error: cannot find ground from its name in the C::E system!')
# make the shaking motion
my_floor.SetBodyFixed(False)
link_shaker = chrono.ChLinkLockLock()
link_shaker.Initialize(my_floor, my_ground, chrono.CSYSNORM)
my_system.Add(link_shaker)
my_functA = chrono.ChFunction_Sine(0,1.4,0.06)
my_functA.thisown = 0
my_functB = chrono.ChFunction_Sine(0,0.1,1)
my_functB.thisown = 0
my_funct = chrono.ChFunction_Operation()
my_funct.Set_fa(my_functA)
my_funct.Set_fb(my_functB)
my_funct.Set_optype(chrono.ChOP_MUL)
my_funct.thisown = 0
link_shaker.SetMotion_X(my_funct)
if m_visualization == "pov":
# ---------------------------------------------------------------------
#
# Render a short animation by generating scripts
# Ramp function
# -------------
f_ramp = chrono.ChFunction_Ramp()
f_ramp.Set_ang(0.1) # angular coefficient
f_ramp.Set_y0(0.1) # y value at x = 0
# Evaluate the function and its first derivative at a given value
y = f_ramp.Get_y(10)
yd = f_ramp.Get_y_dx(10)
print(' Ramp function f(10) = ', y, ', 1st derivative df/dx(10) = ', yd)
# Sine function
# -------------
f_sine = chrono.ChFunction_Sine()
f_sine.Set_amp(2) # amplitude
f_sine.Set_freq(1.5) # frequency
# Evaluate the function and its derivatives at 101 points in [0,2] and write to file
sine_file = open(out_dir + "/f_sine.out","w+")
for i in range(101):
x = i / 50.0
y = f_sine.Get_y(x)
yd = f_sine.Get_y_dx(x)
ydd = f_sine.Get_y_dxdx(x)
sine_file.write("%f %f %f %f\n" % (x, y, yd, ydd))
sine_file.close()
# Custom function
# ---------------
# In this example we impose position and rotation of a body shape respect to absolute reference,
# using the following methods:
#
# position: use a triplet of X,Y,Z ChFunction objects
# rotation: use a fixed axis of rotation and an angle(time) function defined via a ChFunction
# Create the object to move
mmoved_1 = chrono.ChBodyEasyMesh(
chrono.GetChronoDataFile("models/support.obj"), 1000, True, True, False)
system.Add(mmoved_1)
mmoved_1.SetPos(chrono.ChVectorD(-0.5, 0, 0))
# Create a position function p(t) from three x,y,z distinct ChFunction objects,
# in this case two sine functions on y and z, whereas x remains constant 0 by default.
f_xyz = chrono.ChFunctionPosition_XYZfunctions()
f_xyz.SetFunctionY(chrono.ChFunction_Sine(0, 0.5, 0.5))
f_xyz.SetFunctionZ(chrono.ChFunction_Sine(0, 0.5, 0.5))
# Create a rotation function q(t) from a angle(time) rotation with fixed axis:
f_rot_axis = chrono.ChFunctionRotation_axis()
f_rot_axis.SetFunctionAngle(chrono.ChFunction_Sine(0, 0.15, chrono.CH_C_PI))
f_rot_axis.SetAxis(chrono.ChVectorD(1, 1, 1).GetNormalized())
# Create the constraint to impose motion and rotation.
# Note that the constraint acts by imposing the motion and rotation between
# frame1 of Body1 (the impose_1 body in this case) and frame2 of Body2 (the floor
# fixed reference in this case, but it could also be another moving object).
# We initially set both frame1 and frame2 in the same absolute position, btw in the
# main reference of the moved mesh, by setting it during the Initialize() method.
impose_1 = chrono.ChLinkMotionImposed()
system.Add(impose_1)
