/
inverse_kinematics.py
125 lines (112 loc) · 4.4 KB
/
inverse_kinematics.py
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import pybullet as p
import time
import math
from datetime import datetime
import pybullet_data
clid = p.connect(p.SHARED_MEMORY)
if (clid < 0):
p.connect(p.GUI)
#p.connect(p.SHARED_MEMORY_GUI)
p.setAdditionalSearchPath(pybullet_data.getDataPath())
p.loadURDF("plane.urdf", [0, 0, -0.3])
kukaId = p.loadURDF("kuka_iiwa/model.urdf", [0, 0, 0])
p.resetBasePositionAndOrientation(kukaId, [0, 0, 0], [0, 0, 0, 1])
kukaEndEffectorIndex = 6
numJoints = p.getNumJoints(kukaId)
if (numJoints != 7):
exit()
#lower limits for null space
ll = [-.967, -2, -2.96, 0.19, -2.96, -2.09, -3.05]
#upper limits for null space
ul = [.967, 2, 2.96, 2.29, 2.96, 2.09, 3.05]
#joint ranges for null space
jr = [5.8, 4, 5.8, 4, 5.8, 4, 6]
#restposes for null space
rp = [0, 0, 0, 0.5 * math.pi, 0, -math.pi * 0.5 * 0.66, 0]
#joint damping coefficents
jd = [0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1]
for i in range(numJoints):
p.resetJointState(kukaId, i, rp[i])
p.setGravity(0, 0, 0)
t = 0.
prevPose = [0, 0, 0]
prevPose1 = [0, 0, 0]
hasPrevPose = 0
useNullSpace = 1
useOrientation = 1
#If we set useSimulation=0, it sets the arm pose to be the IK result directly without using dynamic control.
#This can be used to test the IK result accuracy.
useSimulation = 1
useRealTimeSimulation = 0
ikSolver = 0
p.setRealTimeSimulation(useRealTimeSimulation)
#trailDuration is duration (in seconds) after debug lines will be removed automatically
#use 0 for no-removal
trailDuration = 15
i=0
while 1:
i+=1
#p.getCameraImage(320,
# 200,
# flags=p.ER_SEGMENTATION_MASK_OBJECT_AND_LINKINDEX,
# renderer=p.ER_BULLET_HARDWARE_OPENGL)
if (useRealTimeSimulation):
dt = datetime.now()
t = (dt.second / 60.) * 2. * math.pi
else:
t = t + 0.01
if (useSimulation and useRealTimeSimulation == 0):
p.stepSimulation()
for i in range(1):
pos = [-0.4, 0.2 * math.cos(t), 0. + 0.2 * math.sin(t)]
#end effector points down, not up (in case useOrientation==1)
orn = p.getQuaternionFromEuler([0, -math.pi, 0])
if (useNullSpace == 1):
if (useOrientation == 1):
jointPoses = p.calculateInverseKinematics(kukaId, kukaEndEffectorIndex, pos, orn, ll, ul,
jr, rp)
else:
jointPoses = p.calculateInverseKinematics(kukaId,
kukaEndEffectorIndex,
pos,
lowerLimits=ll,
upperLimits=ul,
jointRanges=jr,
restPoses=rp)
else:
if (useOrientation == 1):
jointPoses = p.calculateInverseKinematics(kukaId,
kukaEndEffectorIndex,
pos,
orn,
jointDamping=jd,
solver=ikSolver,
maxNumIterations=100,
residualThreshold=.01)
else:
jointPoses = p.calculateInverseKinematics(kukaId,
kukaEndEffectorIndex,
pos,
solver=ikSolver)
if (useSimulation):
for i in range(numJoints):
p.setJointMotorControl2(bodyIndex=kukaId,
jointIndex=i,
controlMode=p.POSITION_CONTROL,
targetPosition=jointPoses[i],
targetVelocity=0,
force=500,
positionGain=0.03,
velocityGain=1)
else:
#reset the joint state (ignoring all dynamics, not recommended to use during simulation)
for i in range(numJoints):
p.resetJointState(kukaId, i, jointPoses[i])
ls = p.getLinkState(kukaId, kukaEndEffectorIndex)
if (hasPrevPose):
p.addUserDebugLine(prevPose, pos, [0, 0, 0.3], 1, trailDuration)
p.addUserDebugLine(prevPose1, ls[4], [1, 0, 0], 1, trailDuration)
prevPose = pos
prevPose1 = ls[4]
hasPrevPose = 1
p.disconnect()