API Interface Documentation¶

Introduction¶

Overview: This document describes the drone control core module of the RflySimSDK drone simulation platform. It provides a drone control base class, various communication control modes, and PID controller implementations, supporting the development and deployment of diverse drone control algorithms.

This module is designed for drone development and simulation testing scenarios and serves as the foundational dependency for users to implement custom drone control logic. The Ctrl class provides the fundamental framework for drone control, while the CtMode class supports selection among different control communication modes (note: Redis mode is supported only in the enterprise edition), accommodating development requirements across different platform versions. The provided PID class is optimized for scenarios with stable control invocation intervals: it avoids redundant time-interval calculations within the controller and instead adjusts control outputs directly via PID parameters. This simplifies parameter tuning in fixed-frequency control scenarios and is suitable for various conventional fixed-frequency control tasks, such as drone position and attitude control.

Quick Start¶

Minimal working example; copy and modify only the essential configurations to run.

from RflySimSDK.ctrl import Ctrl
import time

# 1. Initialize the control object; by default, it uses local UDP connection to control drone ID 1
copter_ctrl = Ctrl(copter_id=1, ip="127.0.0.1")

# 2. Initialize the control loop; use position control mode (ct_mode=2 corresponds to position control), without enabling offboard mode
copter_ctrl.init_loop(ct_mode=2, offboard=False)

# 3. Wait for disarming and initialization to complete
time.sleep(3)

# 4. Command the drone to take off to a height of 10 meters in the NED coordinate system (note: height is negative in NED, so -10 is used here)
copter_ctrl.takeoff(height=-10)

# 5. Wait for takeoff to complete
time.sleep(10)

# 6. Maintain hover by continuously sending control commands to keep the connection alive
while True:
    # Send an empty command to maintain position hover
    if copter_ctrl.is_full_send():
        time.sleep(0.01)

Environment & Dependencies¶

Python Environment: >= 3.8.10
Dependencies: DllSimCtrlAPI, PX4MavCtrlV4, numpy, time
Prerequisites: Before calling this interface, RflySimSDK must be initialized and the RflySimSDK.ctrl module must be imported.

Core Interface Description¶

The module api.py contains configuration variables, helper functions, and core business classes.

Global Constants and Enumerations¶

This section lists all globally accessible constants and enumeration definitions that can be directly referenced in the module.

Standalone Constants¶

None

Global/Standalone Functions¶

None

`Ctrl` Class¶

PX4 flight controller control class, inheriting from PX4MavCtrler, providing basic drone control functionality and supporting connections to both simulated and real PX4 flight controllers.

`init(copter_id=1, ip="127.0.0.1", com="udp", port=0, simulink_dll=False)`¶

Function Description: Initializes a Ctrl object and establishes a connection to the PX4 flight controller (simulation or real hardware). Arguments:

Parameter	Type	Default	Description
copter_id	—	1	Drone ID used to distinguish between multiple drones in multi-drone scenarios
ip	—	127.0.0.1	IP address of the flight controller; for local simulation, the loopback address is used by default
com	—	udp	Communication protocol type; options are `udp` (network communication, commonly used in simulation) or serial communication
port	—	0	Communication port number; 0 indicates automatic port allocation
simulink_dll	—	False	Whether to use Simulink dynamic-link library (DLL) simulation mode; set to `True` for Simulink co-simulation