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import numpy as np
import dartpy as dart
class InputHandler(dart.gui.osg.GUIEventHandler):
def __init__(self, node):
super(InputHandler, self).__init__()
self.node = node
self.force = np.zeros(3)
self.impulse_duration = 0
def handle(self, ea, aa):
if ea.getEventType() == dart.gui.osg.GUIEventAdapter.KEYDOWN:
if ea.getKey() == dart.gui.osg.GUIEventAdapter.KEY_1:
ext_force = np.zeros(3)
ext_force[0] = 40
self.node.set_external_force(ext_force, 100)
return True
if ea.getKey() == dart.gui.osg.GUIEventAdapter.KEY_2:
ext_force = np.zeros(3)
ext_force[0] = -40
self.node.set_external_force(ext_force, 100)
return True
if ea.getKey() == dart.gui.osg.GUIEventAdapter.KEY_3:
ext_force = np.zeros(3)
ext_force[2] = 40
self.node.set_external_force(ext_force, 100)
return True
if ea.getKey() == dart.gui.osg.GUIEventAdapter.KEY_4:
ext_force = np.zeros(3)
ext_force[2] = -40
self.node.set_external_force(ext_force, 100)
return True
return False
class MyWorldNode(dart.gui.osg.RealTimeWorldNode):
def __init__(self, world, skel):
super(MyWorldNode, self).__init__(world)
self.world = world
self.skel = skel
self.dofs = self.skel.getNumDofs()
self.left_heel = self.skel.getBodyNode('h_heel_left')
self.left_foot = [
self.skel.getDof('j_heel_left_1').getIndexInSkeleton(),
self.skel.getDof('j_toe_left').getIndexInSkeleton(),
]
self.right_foot = [
self.skel.getDof('j_heel_right_1').getIndexInSkeleton(),
self.skel.getDof('j_toe_right').getIndexInSkeleton(),
]
self.timestep = world.getTimeStep()
self.Kp = np.eye(self.dofs)
self.Kd = np.eye(self.dofs)
self.torques = np.zeros(self.dofs)
self.q_d = self.skel.getPositions()
# Using SPD results in simple Kp coefficients
for i in range(6):
self.Kp[i, i] = 0.0
self.Kd[i, i] = 0.0
for i in range(6, self.dofs):
self.Kp[i, i] = 400.0
self.Kd[i, i] = 40.0
self.pre_offset = 0
self.ext_force = np.zeros(3)
self.ext_force_duration = 0
self.ext_force_arrow_shape = dart.dynamics.ArrowShape([0, 0, 0], [0, 0, 0])
self.ext_force_simple_frame = dart.dynamics.SimpleFrame()
self.ext_force_simple_frame.setShape(self.ext_force_arrow_shape)
self.ext_force_visual = self.ext_force_simple_frame.createVisualAspect()
self.ext_force_visual.setColor([1.0, 0.0, 0.0])
self.ext_force_visual.hide()
self.world.addSimpleFrame(self.ext_force_simple_frame)
def customPreStep(self):
q = self.skel.getPositions();
dq = self.skel.getVelocities();
constraint_forces = self.skel.getConstraintForces()
# SPD tracking
invM = np.linalg.inv(self.skel.getMassMatrix() + self.Kd * self.timestep)
p = np.matmul(-self.Kp, q + dq * self.timestep - self.q_d)
d = np.matmul(-self.Kd, dq)
ddq = np.matmul(invM, -self.skel.getCoriolisAndGravityForces() + p + d + constraint_forces)
self.torques = p + d + np.matmul(-self.Kd, ddq) * self.timestep
# Ankle strategy for sagital plane
com = self.skel.getCOM()
cop = self.left_heel.getTransform().multiply([0.05, 0, 0])
offset = com[0] - cop[0]
if offset < 0.1 and offset > 0.0:
k1 = 200
k2 = 100
kd = 10
self.torques[self.left_foot[0]] += -k1 * offset + kd * (self.pre_offset - offset)
self.torques[self.left_foot[1]] += -k2 * offset + kd * (self.pre_offset - offset)
self.torques[self.right_foot[0]] += -k1 * offset + kd * (self.pre_offset - offset)
self.torques[self.right_foot[1]] += -k2 * offset + kd * (self.pre_offset - offset)
elif offset > -0.2 and offset < -0.05:
k1 = 2000
k2 = 100
kd = 100
self.torques[self.left_foot[0]] += -k1 * offset + kd * (self.pre_offset - offset)
self.torques[self.left_foot[1]] += -k2 * offset + kd * (self.pre_offset - offset)
self.torques[self.right_foot[0]] += -k1 * offset + kd * (self.pre_offset - offset)
self.torques[self.right_foot[1]] += -k2 * offset + kd * (self.pre_offset - offset)
# Just to make sure no illegal torque is used
for i in range(6):
self.torques[i] = 0
self.skel.setForces(self.torques * 0.8)
# Apply external force
self.ext_force_duration = self.ext_force_duration - 1
if self.ext_force_duration <= 0:
self.ext_force_duration = 0
self.ext_force = np.zeros(3)
spine = self.skel.getBodyNode('h_spine')
spine.addExtForce(self.ext_force)
if self.ext_force_duration > 0:
arrow_head = spine.getTransform().translation()
arrow_tail = arrow_head - self.ext_force / 30
self.ext_force_arrow_shape.setPositions(arrow_tail, arrow_head)
self.ext_force_arrow_shape.setDataVariance(dart.dynamics.Shape.DYNAMIC)
self.ext_force_visual.show()
else:
self.ext_force_arrow_shape.setDataVariance(dart.dynamics.Shape.STATIC)
self.ext_force_visual.hide()
def set_external_force(self, force, duration=10):
self.ext_force = force
self.ext_force_duration = duration
def external_force(self):
return self.ext_force
def main():
world = dart.utils.SkelParser.readWorld('dart://sample/skel/fullbody1.skel')
world.setGravity([0, -9.81, 0])
biped = world.getSkeleton('fullbody1')
biped.getDof('j_pelvis_rot_y').setPosition(-0.20)
biped.getDof('j_thigh_left_z').setPosition(0.15)
biped.getDof('j_shin_left').setPosition(-0.40)
biped.getDof('j_heel_left_1').setPosition(0.25)
biped.getDof('j_thigh_right_z').setPosition(0.15)
biped.getDof('j_shin_right').setPosition(-0.40)
biped.getDof('j_heel_right_1').setPosition(0.25)
biped.getDof('j_abdomen_2').setPosition(0.00)
node = MyWorldNode(world, biped)
# Create world node and add it to viewer
viewer = dart.gui.osg.Viewer()
viewer.addWorldNode(node)
input_handler = InputHandler(node)
viewer.addEventHandler(input_handler)
viewer.setUpViewInWindow(0, 0, 640, 480)
viewer.setCameraHomePosition([3, 1.5, 3], [0, 0, 0], [0, 0, 0])
viewer.run()
if __name__ == "__main__":
main()
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