class Solar_Trainer():
"""
This class creates a base Trainer module to train a SOLAR_GP model on training input-output pairs.
SOLAR_GP models are serialized and sent across a custom topic message interpreted by the SolarPredictor
"""
def __init__(self, njit, degrees, num_inducing, wgen, use_old_Z=False):
"""
njit: number of initial jittered ponts
degrees: degree range of jittered joints
num_inducing: number of inducing points for sparse GP models
wgen: weigted threshold for generating new models
"""
self.solar = []
self.pub_solar = rospy.Publisher('solarGP',
LocalGP,
queue_size=10,
latch=True)
self.njit = njit
self.degrees = degrees
self.num_inducing = num_inducing
self.wgen = wgen
self.use_old_Z = use_old_Z
self.joint_names = []
self.TrainData = []
self.rate = []
self.stop = False
self.pub_traintime = rospy.Publisher('traintime',
Float64,
queue_size=10)
self.x_topic = ""
self.y_topic = ""
rospy.wait_for_service('set_neutral')
self.set_neutral = rospy.ServiceProxy('set_neutral', SetNeutral)
rospy.wait_for_service('jitter')
self.jitter_init = rospy.ServiceProxy('jitter', Jitter)
def initialize(self):
R = rospy.get_param('~train_pub_rate', 100)
self.rate = rospy.Rate(R)
self.buffer_duration = rospy.get_param('~buffer_duration', 0.1)
self.buffer_size = rospy.get_param('~buffer_size', 500)
# Robot-specific setup implemented by derived class
self.setup_robot()
# Jitter robot initially
XI, YI = self.jitter_robot()
num_joints = np.size(YI, 1)
# Create and initialize SOLAR_GP model
self.solar = LocalModels(self.num_inducing,
wgen=self.wgen,
xdim=3,
ndim=num_joints * 2)
self.solar.initializeF(XI, YI)
# Serialize SOLAR_GP model into custom message and publish
SolarMsg = self.constructMsg(self.solar)
self.pub_solar.publish(SolarMsg)
# Create Data buffer listening on training input-output topics
self.TrainData = DataBuffer(self.x_topic, self.y_topic,
self.joint_names, self.buffer_duration,
self.buffer_size)
def setup_robot(self):
print("Setup Robot not implemented")
return False
def jitter_robot(self):
XI = []
YI = []
print("Jitter Robot not implemented")
# Service based implementation
# self.set_neutral()
# self.TrainData = DataBuffer(self.x_topic, self.y_topic, self.joint_names, self.buffer_duration, self.buffer_size)
# self.jitter_init(self.njit, self.degrees)
#
# XI = np.asarray(self.TrainData.Xexp).reshape(len(self.TrainData.Xexp),3)
# YI = np.asarray(self.TrainData.Yexp).reshape(len(self.TrainData.Yexp),len(self.joint_names))
# rospy.loginfo("Number of initial points: %s", len(XI))
# self.TrainData.clear()
return XI, YI
def jitter(self, n, Y_init, deg=5):
"""
Randomly sample joint states within specified degree range from initial joint position
"""
max_rough = 0.0174533
pert = deg * max_rough * np.random.uniform(-1., 1.,
(n, np.size(Y_init, 1)))
Y_start = Y_init + pert
return Y_start
def constructMsg(self, local):
"""
Serializes SOLAR_GP object into custom ROS topic msg
"""
LocMsg = LocalGP()
L = []
for count, m in enumerate(local.Models):
GP = OSGPR_GP()
GP.kern_var = m.kern.variance[0]
GP.kern_lengthscale = np.array(m.kern.lengthscale).tolist()
GP.likelihood_var = m.likelihood.variance[0]
GP.xmean = local.LocalData[count][2][0].tolist()
GP.ymean = local.LocalData[count][3][0].tolist()
GP.numloc = local.LocalData[count][0]
Z = np.array(m.Z)
Z_old = np.array(m.Z_old)
mu_old = np.array(m.mu_old)
Su_old = np.array(m.Su_old)
Kaa_old = np.array(m.Kaa_old)
X_arr = []
Y_arr = []
Z_arr = []
Z_old_arr = []
mu_old_arr = []
Su_old_arr = []
Kaa_old_arr = []
for j in range(0, np.shape(m.X)[0]):
X_row = Arrays()
Y_row = Arrays()
X_row.array = np.array(m.X[j, :]).tolist()
Y_row.array = np.array(m.Y[j, :]).tolist()
X_arr.append(X_row)
Y_arr.append(Y_row)
for j in range(0, np.shape(Z)[0]):
Z_row = Arrays()
Z_row.array = Z[j, :].tolist()
Z_arr.append(Z_row)
for j in range(0, np.shape(Z_old)[0]):
Z_old_row = Arrays()
mu_old_row = Arrays()
Su_old_row = Arrays()
Kaa_old_row = Arrays()
Z_old_row.array = Z_old[j, :].tolist()
mu_old_row.array = mu_old[j, :].tolist()
Su_old_row.array = Su_old[j, :].tolist()
Kaa_old_row.array = Kaa_old[j, :].tolist()
Z_old_arr.append(Z_old_row)
mu_old_arr.append(mu_old_row)
Su_old_arr.append(Su_old_row)
Kaa_old_arr.append(Kaa_old_row)
GP.X = X_arr
GP.Y = Y_arr
GP.Z = Z_arr
GP.Z_old = Z_old_arr
GP.mu_old = mu_old_arr
GP.Su_old = Su_old_arr
GP.Kaa_old = Kaa_old_arr
L.append(GP)
LocMsg.localGPs = L
LocMsg.W = local.W.diagonal().tolist()
LocMsg.M = local.M
LocMsg.xdim = local.xdim
LocMsg.ndim = local.ndim
return LocMsg
def run(self):
while not rospy.is_shutdown() and not self.stop:
t1 = time.time()
# Skip training if data buffer is empty
if not self.TrainData.Xexp:
continue
else:
try:
# Grab training pairs from buffer
Xexp = np.asarray(self.TrainData.Xexp).reshape(
len(self.TrainData.Xexp), 3)
Y = np.asarray(self.TrainData.Yexp).reshape(
len(self.TrainData.Yexp), len(self.joint_names))
Yexp = self.solar.encode_ang(Y)
except:
continue
# Clear buffer
self.TrainData.clear()
try:
# Train drifting model and save trained hyperparameters
mdrift = self.solar.doOSGPR(Xexp,
Yexp,
self.solar.mdrift,
100,
use_old_Z=True,
driftZ=False)
mkl = []
for j in range(0, self.solar.xdim):
mkl.append(1 / (mdrift.kern.lengthscale[j]**2))
W = np.diag(mkl)
self.solar.W = W
self.solar.mdrift = mdrift
except:
pass
# Partition training pairs
self.solar.partition(Xexp.reshape(len(Xexp), self.solar.xdim),
Yexp.reshape(len(Yexp), self.solar.ndim))
try:
# Train SOLAR_GP model
self.solar.train()
except:
pass
# Construct and publish custom SOLAR_GP ROS topic
LocMsg = self.constructMsg(self.solar)
self.pub_solar.publish(LocMsg)
# Publish training time
t2 = time.time()
self.pub_traintime.publish(t2 - t1)
self.rate.sleep()
" Train 'drift' GP"
if i % drift == 0:
mdrift = local.doOSGPR(Xtot[-drift:], Ytot[-drift:], local.mdrift,num_inducing ,use_old_Z=False)
mkl = []
for j in range(0, local.xdim):
mkl.append(1/(mdrift.kern.lengthscale[j]**2))
W = np.diag(mkl)
#W = np.diag([1/(mdrift.kern.lengthscale[0]**2), 1/(mdrift.kern.lengthscale[1]**2)])
local.W = W
local.mdrift = mdrift
"Partition experience "
local.partition(Xexp.reshape(len(Xexp),local.xdim),Yexp.reshape(len(Yexp),local.ndim), flag = partition_flag)
# local.train()
" Train Local Models "
try:
local.train(flag = train_flag)
except:
pass
t2 = time.time()
tc[i-1]= t2-t1
error = np.linalg.norm(X_test[i]-Xexp)
Error = np.hstack((Error,error))
i +=1