main.py

'''
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        _\///________\///______________\///________\///______________\////////////___________________\///////////_____

THIS IS THE HALCYON ADAPTIVE DIRECTOR SYSTEM

This is a pre-alpha, it contains all the usual bug of pre-alpha code, its buggy, its unstable and, it is entirly untested with no redundent saftey.

DO NOT FLY THIS CODE

'''

import pymavlink
from pymavlink import mavutil, mavwp
import pymavlink
import time
from multiprocessing import Process, active_children
import numpy as np
from time import sleep
import signal
import sys
import json

global FailSafe_Ready
FailSafe_Ready = False

class Link(object):
    def __init__(self, address):
        self.Waypoint_Loader = mavwp.MAVWPLoader()
        self.connection = mavutil.mavlink_connection(address)
        print("Connection Established.")
        self.connection.wait_heartbeat()
        print("Heartbeat recived.")
        print("Link Ready.")

        #Remove later
        #self.connection.set_mode_manual()  Does not work, makes sense why

    def Do_Takeoff(self, mission_item):# Working
        '''Uploads the waypoints needed to execute the takeoff run'''
        #Extract variables
        self.latitude, self.longditude, self.altitude, self.minimum_Pitch = mission_item()
        print("Takeoff", self.latitude, self.longditude, self.altitude, self.minimum_Pitch)
        #Generate waypoint
        self.point = mavutil.mavlink.MAVLink_mission_item_message(self.connection.target_system, self.connection.target_component, 0, mavutil.mavlink.MAV_FRAME_GLOBAL_RELATIVE_ALT, mavutil.mavlink.MAV_CMD_NAV_TAKEOFF, 0, 1, self.minimum_Pitch[0], 0, 0, 0, (float(self.latitude[0])), (float(self.longditude[0])), self.altitude[0])
        #Add to planner
        self.Waypoint_Loader.add(self.point)
        #Upload
        self.Send_waypoints()

    def Do_Waypoints(self, mission_item):#Working
        ''' Uploads a sequence of way points'''
        self.latitude, self.longditude, self.radius, self.pass_radius, self.altitude = mission_item()
        print(mission_item())
        for self.mission_item_index in range(0,len(self.latitude)):
            self.point = mavutil.mavlink.MAVLink_mission_item_message(self.connection.target_system, self.connection.target_component, self.mission_item_index, mavutil.mavlink.MAV_FRAME_GLOBAL_RELATIVE_ALT, mavutil.mavlink.MAV_CMD_NAV_WAYPOINT, 0, 1, 0, (float(self.radius[self.mission_item_index])), (float(self.pass_radius[self.mission_item_index])), 0, (float(self.latitude[self.mission_item_index])), (float(self.longditude[self.mission_item_index])), self.altitude[self.mission_item_index])
            self.Waypoint_Loader.add(self.point)
        self.Send_waypoints()
    def Do_Landing(self, mission_item):
        '''Needs 2 waypoints to define the landing slope'''
        self.latitude, self.longditude, self.altitude = mission_item()


    def Send_waypoints(self): #Working
        '''Uploads a sequence of waypoints, this is normal flight'''
        print("Uploading mission")
        #Clears the current sequence present on the flight controller
        self.connection.waypoint_clear_all_send()
        #Informs the FC how many waypoints are to be uploaded
        self.connection.waypoint_count_send(self.Waypoint_Loader.count())
        print("waypoint count",self.Waypoint_Loader.count())
        for i in range(self.Waypoint_Loader.count()):
            #Waits for FC to request next mission item
            self.msg = self.connection.recv_match(type=['MISSION_REQUEST'],blocking=True)
            #Send next item in sequence
            self.connection.mav.send(self.Waypoint_Loader.wp(self.msg.seq))
        #Waits for mission to be accepted
        self.msg = self.connection.recv_match(type=['MISSION_ACK'],blocking=True)

    def Send_Message_To_GCS(self, message): #Not implemented
        '''Send a status message to be displayed the Qgroudcontrol'''
        pass
    def set_pwm(self, channel, position):
        '''Sets a specific rc channel to specific position'''
        self.rc_channel_values = [65535 for _ in range(18)]
        self.rc_channel_values[channel- 1] = position
        self.connection.mav.rc_channels_override_send(self.connection.target_system,self.connection.target_component,*self.rc_channel_values)
    def disarm(self):
        '''Force disarms drone'''
        self.connection.mav.command_long_send(self.connection.target_system, self.connection.target_component, mavutil.mavlink.MAV_CMD_COMPONENT_ARM_DISARM, 0,0,21196,0,0,0,0,0)
        return self.connection.recv.match(type='COMMAND_ACK', blocking = True)
    def set_geofence(self, fence):
        self.latitude, self.longditude = fence()
        self.link.mav.command_long_send(self.connection.target_system, self.connection.target_component,mavutil.mavlink.MAV_CMD_DO_FENCE_ENABLE, 0, 1, 0, 0, 0, 0, 0, 0)
        self.fence_vertex = [self.connection.mav.mission_item_encode(self.connection.target_system,
                                                                     self.connection.target_component,
                                                                     i,
                                                                     mavutil.mavlink.MAV_FRAME_GLOBAL_RELATIVE_ALT,
                                                                     mavutil.mavlink.MAV_CMD_NAV_FENCE_POLYGON_VERTEX_INCLUSION,
                                                                     0,
                                                                     0,
                                                                     i,
                                                                     1,
                                                                     0,
                                                                     0,
                                                                     tuple(self.latitude[i]),
                                                                     tuple(self.longditude[i]),
                                                                     0) for i in range(0,len(self.latitude)) ]
        self.connection.mav.mission_count_send(self.connection.target_system, self.connection.target_component,len(self.fence_vertex))
        self.msg = self.connection.recv_match(type='MISSION_ACK', blocking=True)
        for i, vertex in enumerate(self.fence_vertex):
            self.connection.mav.mission_item_send

            self.msg = self.connection.recv_match(type='MISSION_ACK', blocking=True)
        pass



class Path(object):
    '''Defines a path for the drone to follow'''
    def __init__(self, latitude = None, longditude = None, radius = 5, p_rad = 0, altitude = 60):
        self.latitude = latitude     #Latitude
        self.longditude = longditude #Longditude
        self.altitude = altitude     #Landing waypoint altitude
        self.radius = radius         #Way point acceptance radius
        self.pass_radius = p_rad        #Direction to pass the way point
        self.altitude = altitude     #Target waypoint altitude
    def __call__(self):
        return self.latitude, self.longditude, self.radius, self.pass_radius, self.altitude

class Takeoff(object):
    "Defines the takeoff"
    def __init__(self, latitude = None, longditude = None, altitude = 50, minimum_pitch = 15):
        self.latitude = latitude     #Landing Latitude
        self.longditude = longditude #Landing Longditude
        self.altitude = altitude     #Landing waypoint altitude
        self.minimum_Pitch = minimum_pitch
    def __call__(self):
        return self.latitude, self.longditude, self.altitude, self.minimum_Pitch

class HALO(object):
    '''The Dynamic Auto Landing mission item instructs the flight director to perform the relevent actions'''
    def __init__(self, index, latitude = None, longditude = None, heading = None radius= 30, altitude = 60):
        self.latitude = latitude     #Landing Latitude
        self.longditude = longditude #Landing Longditude
        self.altitude = altitude     #Landing waypoint altitude
        self.Heading = heading #Angle of the runway
        self.Landing_Angle = 20 #Decent Angle
    def __call__(self):
        return self.latitude, self.longditude, self.altitude, self.Heading, self.Landing_Angle

class PCR(object):
    '''This mission item in formed the flight director to monitor the aircraft position and release the cargo at the optimal moment'''
    def __init__(self, latitude = None, longditude = None, altitude = 30):
        self.latitude = latitude     #Latitude
        self.longditude = longditude #Longditude
        self.altitude = altitude     #Target waypoint altitude
    def __call__(self):
        return self.latitude, self.longditude, self.altitude

class Fence(object):
    '''Contains the coordinates of vertexes of the geofence'''
    def __init__(self, latitude, longditude):
        self.latitude = latitude     #Latitude
        self.longditude = longditude #Longditude
    def __call__(self):
        return self.latitude, self.longditude
    def __str__(self):
        pass


class main():
    def __init__(self):
        print("PRERELEASE - DO NOT FLY")
        '''WGS84 is used with the meridian at greenwich so no angular offset is needed'''

        '''Parameter List'''
        self.earth_geoid_radius = 6378137.0 #Meters
        self.cargo_release_time = 0.25 #Time taken for the cargo to exit the aircraft
        self.cargo_relased = False
        self.FS_Maximum_Period = 1 #second
        self.Velocity_FS_Threshold = [0,30]# Meters per second, keeps the done in line with competiton rules
        self.Altitude_FS_Threshold = [0,120]#Above altitude, keeps the drone in line with regulations
        self.Battery_Voltage_FS_Threshold = [0,24]#Volts, prevents brown outs
        self.Battery_Current_FS_Threshold = [0,100]#Amps, prevents catastrophic short circuit

        '''Runs at system boot'''
        self.link = Link("/dev/ttyACM0") #Establishes communciation with the flight controller.
        signal.signal(signal.SIGINT, self.keyboard_interupt_handler) #Stop people accidently crashing the flight controller while in flight.

        '''Start the Failsafe watchdog'''
        #self.FailSafe_Process = Process(target = self.Failsafe_Watchdog) #Defines the Failsafe watch dog daughter process.
        #self.FailSafe_Process.start() #Starts the Failsafe process, this must be started before all other processes to ensure saftey.
        print("Watchdog Active.")

        '''Load Plane Parameters'''
        self.ret = self.Load_Parameters()
        if not self.ret:
            print("Params Loaded.")
        else: # PARAM LOADING FAILED
            print("Failed to Load parameters")
            sys.exit()
        '''Loads geofence from json'''
        self.ret, self.fence = self.Load_geofence()
        if not self.ret:
            print("Geofence Loaded Successfully.")
        else:
            print("Failed to Load geofence")
            sys.exit()

        '''Uploads Geofence'''
        # TODO:
        '''Loads mission from json'''
        self.ret, self.mission = self.Load_mission()
        if not self.ret:
            print("Mission Loaded Successfully.")
        else: # MISSION LOADING FAILED
            print("Failed to Load Mission")
            sys.exit()
        self.mainloop_process = Process(target = self.mainloop) #Define the
        self.mainloop_process.start()

    def Heuristic_Automatic_Landing_Operation(self, item):# HALO
        '''A fully automatic heuristic algorithum that optimises the landing heading and flight path angle'''
        '''Extract struct data'''
        self.latitude, self.longditude, self.altitude, self.Heading, self.Landing_Angle = item()
        '''Select Landing Direction'''
        self.Current_Wind_Angle = 0
        self.Angle_Choices = [self.angle, self.angle-180]
        self.Angular_Difference = self.Angular_Choices-self.Current_Wind_Angle
        self.Max_Angle_index = np.argmax(self.Angular_Difference)
        self.Landing_angle = self.Angle_Choices[self.Max_Angle_index]
        if self.Landing_angle<0:
            self.Landing_angle += 360
        '''We must now generate the landing path waypoints'''
        '''One point will be at the Final landing Location'''
        self.Landing_Path_Ground_Track_Length =
        pass

    def distance(x,y):

            self.dist = np.sqrt((x-j)**2 + (y-k)**2)
            return self.dist

    def time(x0,y0,u_x,u_y,a):

        self.t  = np.linspace(0,60,1000000) #array of different(1000000) time intervals between 0-60 seconds

        self.s_x = u_x*self.t + (1/2)*(a)*(self.t**2) #array of different displacement in x direction from current position to final position after time t traveled with speed u_x
        self.s_y = u_y*self.t + (1/2)*(a)*(self.t**2) #array of different displacement in y direction from current position to final position after time t traveled with speed u_x
        self.x = x0 + self.s_x #array of x distances from x axis at time t
        self.y = y0 + self.s_y #arrya of y distsnces from y axis at time t

        self.d = distance(self.x, self.y) #array of distance from (x,y) to (j,k)

        self.t_min = self.t[self.d.argmin()] #time at minimum distance

        return self.t_min

    def Precision_Cargo_Release(self, item):# PCR
        '''Uses onboard velocity time and position estimations to accuratly release the cargo'''
        self.cargo_relased = False
        self.lead_lag_distance = 10 #Meters
        self.angular_leag_lag_distance = 10/self.earth_geoid_radius #Radians
        self.cargo_release_time_threshold = 0.1 #seconds
        self.wp_latitude, self.wp_longditude, self.wp_alt = item()
        #Requests wind vectors data stream
        self.msg = pymavlink.mavutil.mavlink.MAVLink_request_data_stream_message(self.link.connection.target_system,self.link.connection.target_component,pymavlink.mavutil.mavlink.MAV_DATA_STREAM_ALL,1,1)
        #Sends message
        self.link.connection.mav.send(self.msg)
        print("Message sent")
        #Wait for message to be recived
        self.msg = self.link.connection.recv_match(type='WIND', blocking=True, timeout = 2)
        if self.msg == None:
            self.err = True
            print("No wind convention available.")
        else:
            print("Wind convention found.")
            print(self.msg)
            self.err = False
        '''Extract wind vector data'''
        if self.err:
            self.wind_heading = 2*np.pi*(45/360)
        else:
            #Computes wind heading
            self.wind_heading = np.atan2([self.E_wind],[self.N_wind]) #Radians
        '''Compute leading and lagging points'''
        self.lagging_point = [self.wp_latitude, self.wp_longditude] + [self.angular_leag_lag_distance*np.cos(self.wind_heading),self.angular_leag_lag_distance*np.sin(self.wind_heading)] #Its not unresonable to approximate the sphere to a flat plain at this scale and location
        self.leading_point = [self.wp_latitude, self.wp_longditude] - [self.angular_leag_lag_distance*np.cos(self.wind_heading),self.angular_leag_lag_distance*np.sin(self.wind_heading)]
        '''Generate the path'''
        self.Latitudes = [self.leading_point[0], self.wp_latitude, self.lagging_point[0]]
        self.Longditudes = [self.leading_point[1], self.wp_longditude, self.lagging_point[1]]
        self.PCR_path = Path(self.Latitudes, self.Longditudes,[5,5,5], [0,0,0], [self.wp_alt,self.wp_alt,self.wp_alt])
        '''Upload Path'''
        self.link.Do_Waypoints(self.PCR_path)

        '''
        At this point the aircraft should be heading toward the start of the drop run, we should wait for the first waypoint to be passed
        once its passed we can move to active monitoring and wait for the drop time to be zero
        '''
        self.passed = False
        while self.passed == False:
            #Collect current mission message
            self.msg = self.link.connection.recv_match(type='MISSION_CURRENT', blocking=True, timeout = 2)
            #Extract the current mission sequence index
            #if :
            #    self.passed = True
            #else:
            #    pass

        '''Starts monitoring position and release time'''
        # u_x = #current speed in x axis
        # u_y = #current speed in y axis
        # x0 = self.longitude #x coordinate of current position
        # y0 = self.latitude #y coordinate of current position
        # a = 0 #current accelaration #Assusimg Average acceleration is 0
        # j = #x coordinate of drop
        # k = #y coordinate of drop



        self.time_to_CA = time(x0,y0,u_x,u_y,a)

        '''Release cargo, does t<=0'''
        while not self.cargo_relased:
            #Radius of instantanious path
            self.radius = self.v/self.d_heading
            #Compute the location of the centre of rotation
            if self.d_heading>0: # Centre of rotation will be to te right of the aircraft
                self.COR = [self.radius*np.cos(self.heading),-self.radius*np.sin(self.heading)]+self.position# The global position of the centre of rotation
            elif self.d_heading<0: # Centre of rotation will be to the left of the aircraft
                self.COR = [-self.radius*np.cos(self.heading),self.radius*np.sin(self.heading)]+self.position
            else: # Centre of rotation  is at infinity
                pass
            #Angle from North to plane WRT centre of rotation
            self.plane_angle_from_cor =  np.atan2()
            #Angle from North to target WRT centre of rotation
            self.target_angle_from_cor = np.atan2()
            #Time to closest approach
            self.time_to_CA = (self.target_angle_from_cor-self.plane_angle_from_cor)/self.d_heading
            if self.time_to_CA<=self.cargo_release_time_threshold:
                self.link.set_pwm(7,2200)# Moves release servo to open position
                self.cargo_relased = True


    def Load_Parameters(self): #Wokring but not realy needed
        '''Loads Program Parameters'''
        self.ret = False
        self.param_data = json.load(open("param.json","r"))
        self.param_items = self.param_data.keys()
        return self.ret

    def Load_geofence(self): #Working
        '''Loads the geofence verticies from a JSON file on the SD card'''
        self.Geofence_Latitude = []
        self.Geofence_Longditude = []
        self.ret = True
        try:
            self.geofence_data = json.load(open("GeoFence.json","r" ))
            self.verticies = self.geofence_data.keys()
            for self.vertex in self.verticies:
                self.Geofence_Latitude.append(float(self.geofence_data[self.vertex]["Latitude"]))
                self.Geofence_Longditude.append(float(self.geofence_data[self.vertex]["Longditude"]))
            self.ret = False
        except:
            print("Error encountered, unable to load geofence")
            self.ret = True
        return self.ret, Fence(self.Geofence_Latitude, self.Geofence_Longditude)

    def Load_mission(self): #Working
        '''Loads in mission waypoints from a JSON file on an SD card'''
        self.Mission_objects = []
        self.ret = False
        try:
            self.mission_data = json.load(open("Mission.json","r"))
            self.mission_sections = self.mission_data.keys()
            for self.mission_section in self.mission_sections:
                self.section_type = self.mission_data[self.mission_section]["Type"]
                if self.section_type == "TKOF":
                    self.Minimum_Pitch = [float(self.mission_data[self.mission_section]["TKOF_Options"]["Minimum_Pitch"])]
                    self.Latitude = [float(self.mission_data[self.mission_section]["TKOF_Options"]["Latitude"])]
                    self.Longditude = [float(self.mission_data[self.mission_section]["TKOF_Options"]["Longditude"])]
                    self.Altitude = [float(self.mission_data[self.mission_section]["TKOF_Options"]["Altitude"])]
                    self.Mission_objects.append(Takeoff(self.Latitude, self.Longditude, self.Altitude, self.Minimum_Pitch))
                elif self.section_type == "WP":
                    self.Latitude = []
                    self.Longditude = []
                    self.Altitude = []
                    self.Acceptance_Radius = []
                    self.Pass_Distance = []
                    for self.Mission_item in self.mission_data[self.mission_section]["Waypoints"].keys():
                        self.Latitude.append(self.mission_data[self.mission_section]["Waypoints"][self.Mission_item]["Latitude"])
                        self.Longditude.append(self.mission_data[self.mission_section]["Waypoints"][self.Mission_item]["Longditude"])
                        self.Altitude.append(self.mission_data[self.mission_section]["Waypoints"][self.Mission_item]["Altitude"])
                        self.Acceptance_Radius.append(self.mission_data[self.mission_section]["Waypoints"][self.Mission_item]["Acceptance_Radius"])
                        self.Pass_Distance.append(self.mission_data[self.mission_section]["Waypoints"][self.Mission_item]["Pass_Distance"])
                    self.Mission_objects.append(Path(self.Latitude, self.Longditude, self.Acceptance_Radius, self.Pass_Distance, self.Altitude))
                elif self.section_type == "PCR":
                    self.Latitude = [self.mission_data[self.mission_section]["PCR_Data"]["Latitude"]]
                    self.Longditude = [self.mission_data[self.mission_section]["PCR_Data"]["Longditude"]]
                    self.Mission_objects.append(PCR(self.Latitude, self.Latitude))
                elif self.section_type == "HALO":
                    self.Latitude = [self.mission_data[self.mission_section]["HALO_Data"]["Latitude"]]
                    self.Longditude = [self.mission_data[self.mission_section]["HALO_Data"]["Longditude"]]
                    self.Altitude = [self.mission_data[self.mission_section]["HALO_Data"]["Altitude_Abort"]]
                    self.Heading = [self.mission_data[self.mission_section]["HALO_Data"]["Heading"]]
                    self.Mission_objects.append(HALO(self.Latitude, self.Latitude, self.Altitude, self.Heading))
                else:
                    print("Mission item unknown")
        except:
            self.ret = True
        return self.ret, self.Mission_objects

    def Failsafe_Action(self): #Working
        '''
        The actions of the FTS must aim to safely land the UA as soon as possible after initiation.
        For Fixed Wing aircraft, the throttle shall be set to ‘engine off’ and the control surfaces
        set to initiate a rapid spiral descent.
        For hybrid aircraft, the aircraft shall not transition between hover and forward flight
        following any activation of FTS or Failsafes.
        Other actions could include deployment of a recovery parachute.
        Full aileron left
        Full up elevator
        Full rudder left
        Initiates a death spiral
        '''
        #MUST CHANGE MODE TO Stabalized
        # If in no failsafe region override.
        self.link.set_pwm(2,1900)# Elevator
        self.link.set_pwm(1,1900)# Aileron
        self.link.set_pwm(4,1900)# Rudder
        self.link.set_pwm(3,500) #Throttle

    def Failsafe_Watchdog(self):
        '''Monitors system parameters to ensure complicate with all failsafe conditions'''
        '''This method also enacts the failsafe protocol when nessecary to maintain the saftey of ground staff'''
        '''
        This method must monitor:
        The failsafe watchdog to ensure proper functioning, is the failsafe watchdog running sufficently fast?
        geofence compliance
        minimum altitude compliance
        maximum speed compliance
        battery voltage compliance
        minimum speed compliance
        '''
        self.FS_Maximum_Period = 1 #second
        self.Velocity_FS_Threshold = [0,30]# Meters per second, keeps the done in line with competiton rules
        self.Altitude_FS_Threshold = [0,120]#Above altitude, keeps the drone in line with regulations
        self.Battery_Voltage_FS_Threshold = [0,24]#Volts, prevents brown outs
        self.Battery_Current_FS_Threshold = [0,100]#Amps, catastrophic short circuit
        print("Watchdog Boot.")
        while True:
            sleep(1)
            print("Set state")
            FailSafe_Ready = True
            pass

    def keyboard_interupt_handler(self,q,p): #Working
        '''Execute order 66, kills all the children'''
        '''Interupts the standard keyboard interupt to ensure all processes are correctly terminated.'''
        if not self.link.is_landed():
            print("Craft in flight, command override active.")
        else:
            self.link.disarm()
            self.active = active_children()
            print(len(self.active),"children found.")
            for self.child in self.active:
                self.child.kill()
            print("All child processes terminated.")
            print("Terminating flight director.")
            sys.exit()

    def wait_for_mission_end(self): #Working
        '''
        self.link.connection.waypoint_request_list_send()
        self.msg = self.link.connection.recv_match(type='MISSION_COUNT', blocking=True)
        self.n = self.msg.count
        if self.n == 1:
            print("1 waypoint to be completed.")
        else:
            print(self.n ," waypoints to be completed.")
        while True:
            sleep(0.2) #Slows it down a bit just to save on processing
            self.msg = self.link.connection.waypoint_current()
            if self.msg is None:
                print("None encountered while monitoring")
            if self.msg == self.n:
                print("Mission segment completed")
                break
        '''
        pass

    def mainloop(self):
        print("Waiting for GPS!")
        print("NOT SAFE TOO FLY")#self.link.connection.wait_gps_fix()
        #print(str(self.link.connection.location()))
        print("Waiting for arming!")
        self.link.connection.motors_armed_wait() #Waits for FC to be armed
        print("Motors armed")
        while not self.link.connection.motors_armed(): # Double chekcs
            sleep(2)
            print(self.link.connection.motors_armed())
        print("Motor arm confirmed")

        '''Monitor waypoint mission progress.'''
        for self.mission_item in self.mission:
            if isinstance(self.mission_item, Takeoff):
                self.link.Do_Takeoff(self.mission_item) #Uploads mission waypoints
                self.wait_for_mission_end()
            elif isinstance(self.mission_item, Path):
                print("Path")
                self.link.Do_Waypoints(self.mission_item) #Uploads mission waypoints
                self.wait_for_mission_end()

            elif isinstance(self.mission_item, PCR):
                print("PCR")
                self.Precision_Cargo_Release(self.mission_item) #Monitors and releases cargo

            elif isinstance(self.mission_item, HALO):
                print("Landing")
                self.Heuristic_Automatic_Landing_Operation(self.mission_item)
            else:
                pass
        '''Mission Complete'''
        print("Mission Completed!")
        self.link.disarm()# Force disarms the drone!
        self.link.connection.motors_disarmed_wait()# Waits for confrimation of disarm
        print("Motors Disarmed, it is safe to approach the drone")
        #Try to get it to make some beeps or something

if __name__ == "__main__":
    main()