May 27 extrinsic calibration results are added.

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Rooholla-Khorrambakht 2024-05-27 19:11:35 -04:00
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commit a7fbcfa40e
4 changed files with 1252 additions and 0 deletions

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import gtsam
import numpy as np
from gtsam.symbol_shorthand import X
import yaml
def Vicon2GtExtractParams(params_file):
"""
Read the transformation matrix representing the pose of the vicon marker frame with respect to
the robot IMU frame (B1 body frame) and return as a 4x4 numpy array.
"""
# Initialize variables to None
R_BtoI = None
p_BinI = None
# Open the file and read line by line
with open(params_file) as f:
lines = f.readlines()
reading_R = False
reading_p = False
R_rows = []
p_values = []
for line in lines:
# Check if the line starts reading R_BtoI matrix or p_BinI vector
if "R_BtoI:" in line:
reading_R = True
continue
elif "p_BinI:" in line:
reading_p = True
continue
# Read the values for R_BtoI
if reading_R:
if line.strip(): # not an empty line
R_rows.append(list(map(float, line.split())))
else:
reading_R = False
R_BtoI = np.array(R_rows)
# Read the values for p_BinI
if reading_p:
if line.strip(): # not an empty line
p_values.append(float(line.strip()))
else:
reading_p = False
p_BinI = np.array(p_values)
# Create the 4x4 transformation matrix
T_BtoI = np.identity(4)
T_BtoI[0:3, 0:3] = R_BtoI
T_BtoI[0:3, 3] = p_BinI
return T_BtoI
def KalibrExtractExtrinsics(file_path):
"""
Extract the extrinsic parameters from a given YAML file.
Parameters:
- file_path (str): The path to the input YAML file.
Returns:
- dict: A dictionary containing the extrinsic parameters for each camera.
For each camera:
- T_cx_cy: The camera extrinsic transformation from camera 'y' to camera 'x' coordinates.
Always with respect to the last camera in the chain.
(e.g. for cam1, T_c1_c0 takes cam0 to cam1 coordinates)
- T_cam_imu: IMU extrinsics, transformation from IMU to camera coordinates (T_c_i).
Example:
Given a yaml file with content:
cam0:
...
T_cam_imu: [...]
cam1:
...
T_cn_cnm1: [...]
The function will return a dictionary:
{
"cam0_T_cam_imu": [...],
"T_c1_c0": [...]
}
"""
# Dictionary to store the extrinsic parameters
extrinsic_params = {}
# Open and read the YAML file
with open(file_path, 'r') as f:
yaml_data = yaml.safe_load(f)
# Iterate through the sensors in the yaml data
for sensor, data in yaml_data.items():
# Extract the IMU to camera transformation
# extrinsic_params[sensor]= data['rostopic']
if 'T_cam_imu' in data:
extrinsic_params[f"{sensor}_T_imu"] = np.array(data['T_cam_imu'])
# Extract the camera to camera transformation
if 'T_cn_cnm1' in data:
# Extract camera numbers from the sensor name
current_cam_num = int(sensor.split('cam')[-1])
last_cam_num = current_cam_num - 1 # Last camera in the chain
# Change the key name to use explicit camera numbers
current_cam_name = f"cam{current_cam_num}"
last_cam_name = f"cam{last_cam_num}"
key_name = f"{current_cam_name}_T_{last_cam_name}"
extrinsic_params[key_name] = np.array(data['T_cn_cnm1'])
return extrinsic_params
def KalibrExtractIntrinsics(file_path):
"""
Extract the intrinsic parameters from a given YAML file.
Parameters:
- file_path (str): The path to the input YAML file.
Returns:
- dict: A dictionary containing the intrinsic parameters for each camera.
For each camera:
- intrinsics: Dictionary of intrinsic parameters based on the camera model.
- distortion_coeffs: Dictionary of distortion coefficients based on the distortion model.
- resolution: List containing camera resolution [width, height].
- camera_model: String specifying the camera model.
- distortion_model: String specifying the distortion model.
"""
# Open and read the YAML file
with open(file_path, 'r') as f:
yaml_data = yaml.safe_load(f)
intrinsic_params = {}
for sensor, data in yaml_data.items():
sensor_data = {}
# Extract camera model and intrinsics
camera_model = data['camera_model']
sensor_data['camera_model'] = camera_model
intrinsics = {}
if camera_model == 'pinhole':
intrinsics = {
'fu': data['intrinsics'][0],
'fv': data['intrinsics'][1],
'pu': data['intrinsics'][2],
'pv': data['intrinsics'][3]
}
elif camera_model == 'omni':
intrinsics = {
'xi': data['intrinsics'][0],
'fu': data['intrinsics'][1],
'fv': data['intrinsics'][2],
'pu': data['intrinsics'][3],
'pv': data['intrinsics'][4]
}
# ... add similar conditions for 'ds' and 'eucm'
sensor_data['intrinsics'] = intrinsics
# Extract distortion model and coefficients
distortion_model = data['distortion_model']
sensor_data['distortion_model'] = distortion_model
coeffs = {}
if distortion_model == 'radtan':
coeffs = {
'k1': data['distortion_coeffs'][0],
'k2': data['distortion_coeffs'][1],
'r1': data['distortion_coeffs'][2],
'r2': data['distortion_coeffs'][3]
}
elif distortion_model == 'equi':
coeffs = {
'k1': data['distortion_coeffs'][0],
'k2': data['distortion_coeffs'][1],
'k3': data['distortion_coeffs'][2],
'k4': data['distortion_coeffs'][3]
}
# ... add similar conditions for 'fov' and 'none'
sensor_data['distortion_coeffs'] = coeffs
sensor_data['resolution'] = data['resolution']
intrinsic_params[sensor] = sensor_data
return intrinsic_params
def KalibrExtractDirectory(directory_path):
"""
Process all YAML files in a directory and return camera details.
Parameters:
- directory_path (str): The path to the directory containing YAML files.
Returns:
- dict, dict: Two dictionaries containing extrinsic and intrinsic parameters for each camera.
"""
extrinsic_all = {}
intrinsic_all = {}
# List all files in the directory
for filename in os.listdir(directory_path):
# Check if the file is a YAML file
if filename.endswith(".yaml"):
filepath = os.path.join(directory_path, filename)
rig_name = os.path.splitext(filename)[0] # Get the rig name from the filename without extension
# Extract parameters using previously defined functions
extrinsic_params = KalibrExtractExtrinsics(filepath)
intrinsic_params = KalibrExtractIntrinsics(filepath)
# Rename keys by appending rig_name
for key in extrinsic_params.keys():
extrinsic_all[f"{rig_name}_{key}"] = extrinsic_params[key]
for key in intrinsic_params.keys():
intrinsic_all[f"{rig_name}_{key}"] = intrinsic_params[key]
return extrinsic_all, intrinsic_all
class ExtrinsicCalibrationManager:
"""
A class that manages the relative transformations (SE3) between a suite of sensors using GTSAM.
"""
def __init__(self):
"""
Initializes an SE3ExtrinsicManager object.
"""
self.reset()
def reset(self):
"""
Resets the internal state of the manager.
"""
self.graph = gtsam.NonlinearFactorGraph() # Graph for optimization
self.values = gtsam.Values() # Values in the graph
self.name_to_id = {} # Map of sensor name to ID
self.id_to_name = {} # Map of ID to sensor name
self.latest_assigned_id = -1 # Latest ID assigned to a sensor
self.extrinsics = None # Optimized extrinsics
def add(self, parent, child, R, t, confidence=1):
"""
Add a relative transformation (SE3) between parent and child sensors ${}^{parent} T_{child}$.
@param parent: Name of the parent sensor.
@param child: Name of the child sensor.
@param R: Rotation matrix (3x3) or quaternion (4x1, 1x4, 4,) [qw, qx, qy, qz].
@param t: Translation vector [x, y, z].
@param confidence: Confidence level for the measurement. Defaults to 1.
"""
# Handle the case where R is a quaternion
if R.shape == (4, 1) or R.shape == (1, 4) or R.shape == (4,):
qw = R[0]
qx = R[1]
qy = R[2]
qz = R[3]
R = gtsam.Rot3(qw, qx, qy, qz).matrix()
# Construct a full transformation matrix
T = np.vstack([np.hstack([R, t.reshape(3, 1)]), np.array([0, 0, 0, 1])])
# Handle new sensors
if parent not in self.name_to_id.keys():
self.latest_assigned_id += 1
self.id_to_name[self.latest_assigned_id] = parent
self.name_to_id[parent] = self.latest_assigned_id
self.values.insert(X(self.name_to_id[parent]), gtsam.Pose3())
if child not in self.name_to_id.keys():
self.latest_assigned_id += 1
self.id_to_name[self.latest_assigned_id] = child
self.name_to_id[child] = self.latest_assigned_id
self.values.insert(X(self.name_to_id[child]), gtsam.Pose3())
# Add measurement to the graph
Sigma = gtsam.noiseModel.Diagonal.Sigmas([confidence for _ in range(6)])
self.graph.add(
gtsam.BetweenFactorPose3(
X(self.name_to_id[parent]),
X(self.name_to_id[child]),
gtsam.Pose3(T),
Sigma,
)
)
# Optimize the graph
params = gtsam.LevenbergMarquardtParams()
optimizer = gtsam.LevenbergMarquardtOptimizer(self.graph, self.values, params)
self.extrinsics = optimizer.optimize()
def get(self, parent, child):
"""
Get the relative transformation from the parent sensor to the child sensor.
@param parent: Name of the parent sensor.
@param child: Name of the child sensor.
@return: A 4x4 matrix representing the relative transformation ${}^{reference} T_{child}$.
"""
T_parent = self.extrinsics.atPose3(X(self.name_to_id[parent])).matrix()
T_child = self.extrinsics.atPose3(X(self.name_to_id[child])).matrix()
return np.linalg.inv(T_parent) @ T_child
def get_all(self, reference):
"""
Get transformations of all sensors relative to a given reference sensor.
@param reference: Name of the reference sensor.
@return: A dictionary with keys as "<sensor_name>_wrt_<reference>" and values as 4x4 transformation matrices.
"""
assert (
reference in self.name_to_id.keys()
), "Selected reference frame is not in the graph"
return {
f"{key}_wrt_{reference}": self.get(reference, key)
for key in self.name_to_id.keys()
if key != reference
}
def pose2qt(self, T):
"""
Convert a 4x4 transformation matrix to quaternion and translation vector.
@param T: A 4x4 transformation matrix.
@return: A 4x1 quaternion.
"""
return gtsam.Rot3(T[:3, :3]).quaternion(), T[0:3, 3]
def KalibrExtractSensorToFrameNameMap(param_file):
'''
Given the path to a kalibr calibration yaml file, returns a dictionary mapping sensor names in the yaml file
to the corresponding frame ids as published by realsense_ros ROS2 package. This has been done by inspecting the
rostopic field in the yaml file.
@ param param_file: path to a kalibr calibration yaml file
@ return: dictionary mapping sensor names in the yaml file to the corresponding frame ids as published by realsense_ros ROS2 package.
'''
with open(param_file, 'r') as f:
data = yaml.safe_load(f)
sensor_name_to_frame_id = {}
for sensor in data.keys():
tmp = data[sensor]['rostopic'].split('/')
frame_name = tmp[2]+'_'+tmp[3]+'_optical_frame'
sensor_name_to_frame_id[sensor] = frame_name
return sensor_name_to_frame_id
def KalibrExtractFrameExtrinsics(camera_intrinsics_dir):
'''
Given the directory containing the result of kalibr calibration procedure, returns
a dictionary of 4x4 numpy arrays representing the extrinsics between the parent and child frames
with parent and child frames having similar TF names as the ones published by realsense_ros ROS2 package.
@ param camera_intrinsics_dir: directory containing a collection yaml files from kalibr calibration procedure
@ return: dictionary of 4x4 numpy arrays representing the extrinsics between the parent and child frames info['parent_frame_id:child_frame_id'] = pose
'''
intrinsics_files = os.listdir(camera_intrinsics_dir)
info = {} # info will hold the extrinsics poses between parent frame ids and child frame ids as info['parent_frame_id:child_frame_id'] = pose
for file in intrinsics_files:
param_file = os.path.join(camera_intrinsics_dir,file)
ext_params = KalibrExtractExtrinsics(param_file)
if len(ext_params) == 0:
continue
map = KalibrExtractSensorToFrameNameMap(param_file)
for pose in ext_params:
parent_sensor_name = pose.split('_T_')[0]
child_sensor_name = pose.split('_T_')[-1]
if child_sensor_name == 'imu':
child_frame_id = 'b1_imu_link'
else:
child_frame_id = map[child_sensor_name]
parent_frame_id = map[parent_sensor_name]
info[f'{parent_frame_id}:{child_frame_id}'] = ext_params[pose]
return info

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{
"cells": [
{
"cell_type": "code",
"execution_count": 1,
"metadata": {},
"outputs": [],
"source": [
"from Go2Py.sim.mujoco import Go2Sim\n",
"from Go2Py.robot.model import Go2Model\n",
"import pinocchio as pin \n",
"import numpy as np\n",
"import time"
]
},
{
"cell_type": "code",
"execution_count": 2,
"metadata": {},
"outputs": [],
"source": [
"model = Go2Model()\n",
"model.get"
]
},
{
"cell_type": "code",
"execution_count": 3,
"metadata": {},
"outputs": [],
"source": [
"robot = Go2Sim()"
]
},
{
"cell_type": "code",
"execution_count": 4,
"metadata": {},
"outputs": [],
"source": [
"robot.step()"
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {},
"outputs": [],
"source": [
"omega = robot.getIMU()['gyro']\n",
"def hat(w):\n",
" return np.array([[0., -w[2], w[1]],\n",
" [w[2], 0., -w[0]],\n",
" [-w[1], w[0], 0.]])"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"robot.standUpReset()\n",
"while True:\n",
" time.sleep(0.001)\n",
" robot.setCommands(robot.standing_q, np.zeros(12), np.ones(12)*100, np.ones(12)*0.1, np.zeros(12))\n",
" robot.step() \n",
" trans, quat = robot.getPose()\n",
" state = robot.getJointStates()\n",
" quat = pin.Quaternion(np.hstack([quat[1:],quat[0]]))\n",
" R = quat.matrix()\n",
" T = np.eye(4)\n",
" T[0:3,0:3] = R\n",
" vel = np.zeros(6)\n",
" model.update(state['q'], state['dq'],T,vel)\n",
"\n",
" J = model.getInfo()['J']['FR_foot'][:,6:]\n",
" nle = model.getInfo()['nle'][6:]\n",
" # tau = (robot.data.qfrc_smooth+robot.data.qfrc_constraint)[6:]\n",
" tau = state['tau_est'].squeeze()\n",
" print(np.linalg.pinv(J.T)[0:3]@(tau - nle))"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"question: What exactly is the difference between the local world aligned and local jacobians in the pinocchio? Why it fits my expectations for the FR3 and not the Go2?"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"robot.getJointStates()\n"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": [
"J[3:,:].T"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [],
"source": []
}
],
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