PM Re Architecture (again)

Background

I’m working on it

Reasoning Behind Restructuring

We are once again restructuring path manager! The current goal is to restructure PM so that it focuses more on path management while AM will take care of movement such as calculating roll, pitch, yaw, and adjusting throttle.

State Machine Changes

Some state names have been renamed to better reflect what is happening within the state. resetVariables has been renamed to FlightStageSelectorMode where PM will figure out what stage of flight needs to be executed.

The coordinateTurnElevation state has been removed as it previously calculated roll, pitch, yaw, etc which has been passed onto AM. Now, the desired heading is calculated in one of the flight modes and is passed to AM to make movement calculations.

Main Structure of PM

A diagram of the general flow of Path Manager, including its modes, stages, and states can be found below.

PM has been sectioned into to main modes: CommsWithStateManagerMode, and FlightStageSelectorMode. Within CommsWithStateManagerMode, PM will get the relevant instructions and information from AM, TM, and Sensor Fusion. This retrieval process is separated into three stages CommsWithAMStage, CommsWithTMStage, CommsWithSFStage where PM will get information from both managers and sensor fusion respectively. Note: these may be combined into one stage depending on how State Manager sends us the information.

PM will then enter FlightStageSelectorMode, the main part of the state machine. Within this mode, PM will change flight states if triggered to do so. While flying, PM may enter any of the following flight states: Disarmed, Takeoff, Cruising, Landing, and Landed. Note: a Preflight state may be added. If we are in the Disarmed state or Landed state PM will go back to the start. However, if we are in Takeoff, Cruising, or Landing, PM will execute their respective stages.

Important Structs

Note: These will all be coming from State Manager

PM → AM Struct:

typedef struct CommandsForAM_t{
  WaypointType waypoint_type; 

  // heading unit vector and magnitude
  float heading_dist_x; 
  float heading_dist_y; 
  float heading_dist_z; 
  float heading_magnitude; // Magnitude distance to waypoint target
  double velocity_target; // Target velocity of drone approaching target
} CommandsForAM;

AM → PM Struct:

AM will send to PM an armed flag to signal that we are ready to fly. Additional information TBD

typedef struct CommandsFromAM{
    bool armed;  
} CommandsFromAM;

TM → PM Waypoint Struct:

CV will be sending a list of waypoints during Cruise and Search (sent through TM and SM) where a waypoint is defined below. The start_landing flag will be signaled when a landing pad is found.

struct GpsCoordinates{    
  double longitude;     
  double lattiude; 
};

struct TelemWaypointData {    
  struct GpsCoordinates gps_coords;    
  int waypoint_id; 
};

typedef struct CommandsFroTM{
    bool start_landing;
    int num_waypoints; // number of waypoints in the list 
    TelemWaypointData waypoints[num_waypoints]; 
} CommandsFromTM;