def test_init_elink_branched(self):
robot = ERobot([
ELink(ETS.rz(), name='link1'),
ELink(ETS.tx(1) * ETS.ty(-0.5) * ETS.rz(),
name='link2',
parent='link1'),
ELink(ETS.tx(1), name='ee_1', parent='link2'),
ELink(ETS.tx(1) * ETS.ty(0.5) * ETS.rz(),
name='link3',
parent='link1'),
ELink(ETS.tx(1), name='ee_2', parent='link3')
])
self.assertEqual(robot.n, 3)
for i in range(5):
self.assertIsInstance(robot[i], ELink)
self.assertTrue(robot[0].isrevolute)
self.assertTrue(robot[1].isrevolute)
self.assertTrue(robot[3].isrevolute)
self.assertIs(robot[0].parent, None)
self.assertIs(robot[1].parent, robot[0])
self.assertIs(robot[2].parent, robot[1])
self.assertIs(robot[3].parent, robot[0])
self.assertIs(robot[4].parent, robot[3])
self.assertEqual(robot[0].children, [robot[1], robot[3]])
self.assertEqual(robot[1].children, [robot[2]])
self.assertEqual(robot[2].children, [])
self.assertEqual(robot[3].children, [robot[4]])
self.assertEqual(robot[2].children, [])
def test_jindex(self):
e1 = ELink(rtb.ETS.rz(), jindex=0)
e2 = ELink(rtb.ETS.rz(), jindex=1, parent=e1)
e3 = ELink(rtb.ETS.rz(), jindex=2, parent=e2)
e4 = ELink(rtb.ETS.rz(), jindex=0, parent=e3)
# with self.assertRaises(ValueError):
ERobot([e1, e2, e3, e4], gripper_links=e4)
def test_init_bases(self):
e1 = ELink()
e2 = ELink()
e3 = ELink(parent=e1)
e4 = ELink(parent=e2)
with self.assertRaises(ValueError):
ERobot([e1, e2, e3, e4])
def test_init(self):
l0 = ELink()
l1 = ELink(parent=l0)
r = ERobot([l0, l1], base=sm.SE3.Rx(1.3), base_link=l1)
r.base_link = l1
with self.assertRaises(TypeError):
ERobot(l0, base=sm.SE3.Rx(1.3))
with self.assertRaises(TypeError):
ERobot([1, 2], base=sm.SE3.Rx(1.3))
def test_init_elink_autoparent(self):
links = [
ELink(ETS.rx(), name='link1'),
ELink(ETS.tx(1) * ETS.ty(-0.5) * ETS.tz(), name='link2'),
ELink(ETS.tx(1), name='ee_1')
]
robot = ERobot(links)
self.assertEqual(robot.n, 2)
self.assertIsInstance(robot[0], ELink)
self.assertIsInstance(robot[1], ELink)
self.assertIsInstance(robot[2], ELink)
self.assertTrue(robot[0].isrevolute)
self.assertTrue(robot[1].isprismatic)
self.assertIs(robot[0].parent, None)
self.assertIs(robot[1].parent, robot[0])
self.assertIs(robot[2].parent, robot[1])
self.assertEqual(robot[0].children, [robot[1]])
self.assertEqual(robot[1].children, [robot[2]])
self.assertEqual(robot[2].children, [])
def test_complex(self):
l0 = ELink(rtb.ETS.tx(0.1), rtb.ETS.rx())
l1 = ELink(rtb.ETS.tx(0.1), rtb.ETS.ry(), parent=l0)
l2 = ELink(rtb.ETS.tx(0.1), rtb.ETS.rz(), parent=l1)
l3 = ELink(rtb.ETS.tx(0.1), rtb.ETS.tx(), parent=l2)
l4 = ELink(rtb.ETS.tx(0.1), rtb.ETS.ty(), parent=l3)
l5 = ELink(rtb.ETS.tx(0.1), rtb.ETS.tz(), parent=l4)
r = ERobot([l0, l1, l2, l3, l4, l5])
q = [1, 2, 3, 1, 2, 3]
ans = np.array([[
-0., 0.08752679, -0.74761985, 0.41198225, 0.05872664, 0.90929743
],
[
1.46443609, 2.80993063, 0.52675075, -0.68124272,
-0.64287284, 0.35017549
],
[
-1.04432, -1.80423571, -2.20308833, 0.60512725,
-0.76371834, -0.2248451
], [1., 0., 0.90929743, 0., 0., 0.],
[0., 0.54030231, 0.35017549, 0., 0., 0.],
[0., 0.84147098, -0.2248451, 0., 0., 0.]])
nt.assert_array_almost_equal(r.jacob0(q), ans)
def test_jindex_fail(self):
e1 = ELink(rtb.ETS.rz(), jindex=0)
e2 = ELink(rtb.ETS.rz(), jindex=1, parent=e1)
e3 = ELink(rtb.ETS.rz(), jindex=2, parent=e2)
e4 = ELink(rtb.ETS.rz(), jindex=5, parent=e3)
with self.assertRaises(ValueError):
ERobot([e1, e2, e3, e4])
e1 = ELink(rtb.ETS.rz(), jindex=0)
e2 = ELink(rtb.ETS.rz(), jindex=1, parent=e1)
e3 = ELink(rtb.ETS.rz(), jindex=2, parent=e2)
e4 = ELink(rtb.ETS.rz(), parent=e3)
with self.assertRaises(ValueError):
ERobot([e1, e2, e3, e4])
def test_init_elink(self):
link1 = ELink(ETS.rx(), name='link1')
link2 = ELink(ETS.tx(1) * ETS.ty(-0.5) * ETS.tz(),
name='link2',
parent=link1)
link3 = ELink(ETS.tx(1), name='ee_1', parent=link2)
robot = ERobot([link1, link2, link3])
self.assertEqual(robot.n, 2)
self.assertIsInstance(robot[0], ELink)
self.assertIsInstance(robot[1], ELink)
self.assertIsInstance(robot[2], ELink)
self.assertTrue(robot[0].isrevolute)
self.assertTrue(robot[1].isprismatic)
self.assertFalse(robot[2].isrevolute)
self.assertFalse(robot[2].isprismatic)
self.assertIs(robot[0].parent, None)
self.assertIs(robot[1].parent, robot[0])
self.assertIs(robot[2].parent, robot[1])
self.assertEqual(robot[0].children, [robot[1]])
self.assertEqual(robot[1].children, [robot[2]])
self.assertEqual(robot[2].children, [])
link1 = ELink(ETS.rx(), name='link1')
link2 = ELink(ETS.tx(1) * ETS.ty(-0.5) * ETS.tz(),
name='link2',
parent='link1')
link3 = ELink(ETS.tx(1), name='ee_1', parent='link2')
robot = ERobot([link1, link2, link3])
self.assertEqual(robot.n, 2)
self.assertIsInstance(robot[0], ELink)
self.assertIsInstance(robot[1], ELink)
self.assertIsInstance(robot[2], ELink)
self.assertTrue(robot[0].isrevolute)
self.assertTrue(robot[1].isprismatic)
self.assertIs(robot[0].parent, None)
self.assertIs(robot[1].parent, robot[0])
self.assertIs(robot[2].parent, robot[1])
self.assertEqual(robot[0].children, [robot[1]])
self.assertEqual(robot[1].children, [robot[2]])
self.assertEqual(robot[2].children, [])
def test_invdyn(self):
# create a 2 link robot
# Example from Spong etal. 2nd edition, p. 260
E = rtb.ETS
l1 = ELink(ets=E.ry(), m=1, r=[0.5, 0, 0], name='l1')
l2 = ELink(ets=E.tx(1) * E.ry(),
m=1,
r=[0.5, 0, 0],
parent=l1,
name='l2')
robot = ERobot([l1, l2], name="simple 2 link")
z = np.zeros(robot.n)
# check gravity load
tau = robot.rne(z, z, z) / 9.81
nt.assert_array_almost_equal(tau, np.r_[-2, -0.5])
tau = robot.rne([0, -pi / 2], z, z) / 9.81
nt.assert_array_almost_equal(tau, np.r_[-1.5, 0])
tau = robot.rne([-pi / 2, pi / 2], z, z) / 9.81
nt.assert_array_almost_equal(tau, np.r_[-0.5, -0.5])
tau = robot.rne([-pi / 2, 0], z, z) / 9.81
nt.assert_array_almost_equal(tau, np.r_[0, 0])
# check velocity terms
robot.gravity = [0, 0, 0]
q = [0, -pi / 2]
h = -0.5 * sin(q[1])
tau = robot.rne(q, [0, 0], z)
nt.assert_array_almost_equal(tau, np.r_[0, 0] * h)
tau = robot.rne(q, [1, 0], z)
nt.assert_array_almost_equal(tau, np.r_[0, -1] * h)
tau = robot.rne(q, [0, 1], z)
nt.assert_array_almost_equal(tau, np.r_[1, 0] * h)
tau = robot.rne(q, [1, 1], z)
nt.assert_array_almost_equal(tau, np.r_[3, -1] * h)
# check inertial terms
d11 = 1.5 + cos(q[1])
d12 = 0.25 + 0.5 * cos(q[1])
d21 = d12
d22 = 0.25
tau = robot.rne(q, z, [0, 0])
nt.assert_array_almost_equal(tau, np.r_[0, 0])
tau = robot.rne(q, z, [1, 0])
nt.assert_array_almost_equal(tau, np.r_[d11, d21])
tau = robot.rne(q, z, [0, 1])
nt.assert_array_almost_equal(tau, np.r_[d12, d22])
tau = robot.rne(q, z, [1, 1])
nt.assert_array_almost_equal(tau, np.r_[d11 + d12, d21 + d22])