RoboRally/remote_control/measurement_server.py

129 lines
6.2 KiB
Python

import socketserver
import threading
import time
import json
from queue import Queue
from aruco_estimator import ArucoEstimator
class MeasurementHandler(socketserver.BaseRequestHandler):
def handle(self) -> None:
data = self.request.recv(1024).strip()
cur_thread = threading.current_thread()
print(f"current thread {cur_thread}")
if 'events' in data.decode():
self.request.sendall('subscribed to events\n'.encode())
# send any events in the event queue to the subscriber
while True:
while not self.server.estimator.event_queue.empty():
event = self.server.estimator.event_queue.get()
# we distinguish two kinds of events:
if event[0] == 'response_event':
# 1. for 'response_event' events we expect the event subscriber to give a reply which will then
# by passed on to the response queue for transmitting to the original correspondent
message = event[1]['event']
#print(f"passing command {message} on to subscriber")
self.request.sendall((json.dumps(message) + '\n').encode())
reply = self.request.recv(1024)
#print(f"putting reply {reply} in response queue")
self.server.response_queue.put(reply)
else:
# 2. for other types of events we don't expect a reply and just pass them on to the subscriber
self.request.sendall((json.dumps(event) + '\n').encode())
self.server.estimator.last_event = None
time.sleep(1.0 / self.server.max_measurements_per_second)
elif 'corners' in data.decode():
# send positions of the board markers
corner_estimates = self.server.estimator.corner_estimates
response = {}
for corner, data in corner_estimates.items():
response[corner] = {'x': data['x'], 'y': data['y']}
self.request.sendall((json.dumps(response) + '\n').encode())
elif 'move_grid_blocking' in data.decode():
# if we receive a move_grid event
# ( e.g. move_grid;{"x":1,"y":1,"dimx":10,"dimy":10,"orientation":"^","require_response":True} )
# we compute the corresponding real-world position the robot should drive to
# and then create a new move event which is put in the event queue and will be propagated to the ControlCommander
data_decode = data.decode()
# print("data: ", data_decode)
payload = data.decode().split(';')[1]
grid_pos = json.loads(payload)
# print("grid_pos = ", grid_pos)
pos = self.server.estimator.get_pos_from_grid_point(grid_pos['x'], grid_pos['y'], grid_pos['dimx'],
grid_pos['dimy'], grid_pos['orientation'])
# print("pos = ", pos)
# print("event requiring response")
# put blocking move command in event queue
self.server.estimator.event_queue.put(('response_event',
{'event': ('move_blocking', {'x': pos[0], 'y': pos[1], 'angle': pos[2]})}))
# wait for response of the move command
# TODO this assumes that we wait only for at most one response at a time
# we could add some kind of reference here to handle multiple responses (e.g. id of the response to wait for)
while self.server.response_queue.empty():
pass
reply = self.server.response_queue.get()
# send back response to the original source
#print(f"sending reply {reply} back to correspondent {self.request}")
self.request.sendall(reply)
else:
# send robot position
try:
marker_id = int(data)
except ValueError:
marker_id = None
if marker_id is not None:
if marker_id in self.server.estimator.robot_marker_estimates:
while True:
self.request.sendall((json.dumps(self.server.estimator.robot_marker_estimates[marker_id])
+ '\n').encode())
time.sleep(1.0 / self.server.max_measurements_per_second)
else:
self.request.sendall("error: unknown robot marker id\n".encode())
else:
self.request.sendall("error: data not understood. "
"expected <robot marker id (int)> or 'events'\n".encode())
return
class MeasurementServer(socketserver.ThreadingMixIn, socketserver.TCPServer):
allow_reuse_address = True
def __init__(self, server_address, RequestHandlerClass, estimator, max_measurements_per_second=30):
super().__init__(server_address, RequestHandlerClass)
self.estimator = estimator
self.max_measurements_per_second = max_measurements_per_second
self.response_queue = Queue()
def handle_error(self, request, client_address):
print("an error occurred -> terminating connection")
if __name__ == "__main__":
aruco_estimator = ArucoEstimator(use_realsense=False, robot_marker_ids=[12, 13])
# first we start thread for the measurement server
measurement_server = MeasurementServer(('0.0.0.0', 42424), MeasurementHandler, aruco_estimator,
max_measurements_per_second=30)
server_thread = threading.Thread(target=measurement_server.serve_forever)
server_thread.start()
# now we start the Aruco estimator GUI
aruco_estimator.process_frame()
import sys
from pyqtgraph.Qt import QtCore, QtGui
if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
QtGui.QApplication.instance().exec_()
#with MeasurementServer(('0.0.0.0', 42424), MeasurementHandler, aruco_estimator,
# max_measurements_per_second=30) as measurement_server:
# measurement_server.serve_forever()
# receive with: nc 127.0.0.1 42424 -> 12 + Enter