Guidance, navigation, and control systems are used in many vehicles to achieve precision, reliability, stability, mission path planning, and ... . what are the primary objectives of GNC systems respectively?
The purpose of guidance is provided by the decision-making system, which determines where to go and what tasks to execute through strategies. For instance, in the case of automated delivery drones, the decision-making system needs to determine, based on optimization algorithms, the optimal locations for the drone to deliver goods first in order to achieve the best path or time efficiency.
Regarding navigation, I believe its purpose lies in path planning or trajectory tracking. Taking path planning as an example, it can be further divided into global path planning and local path planning. Global path planning aims to find a collision-free optimal path in a known map using methods such as RRT, PRM, A-star, without considering dynamic obstacles in space. On the other hand, local path planning utilizes information from perception devices like cameras and LiDAR to assist robots in real-time obstacle avoidance planning.
The purpose of control is to calculate the required motor drive control based on the expected path or velocity/angular velocity information obtained from the planning system, using sensors such as IMU and GNSS on the robot's end, to complete the motion control of the carrier.
Guidance is the process of determining the path or trajectory of an aircraft or moving platform to achieve mission objectives from a starting point to an end point. The guidance system is responsible for planning the path and re-planning the path when encountering unexpected situations to ensure the achievement of mission objectives. Guidance systems often need to take into account mission objectives, environmental factors (such as wind speed, obstacles) and the dynamic limitations of the aircraft.
Navigation is the process of determining and maintaining the current position and orientation of an aircraft or robot in the environment. It involves the continuous estimation of the position, speed and attitude of an aircraft relative to the Earth or other reference point. Navigation systems usually rely on GPS/GNSS, inertial measurement unit (IMU), interstellar navigation and other technologies to obtain precise position and movement information.
Control refers to the process of adjusting the motion state of an aircraft or robot through its power system (such as engine, rudder surface, motor), so as to fly or move according to the path planned by the guidance system, and in the face of wind disturbance, gravity changes, etc. Remain stable under external disturbances. The control system needs to respond quickly and accurately to instructions from the guidance and navigation system, and maintain or modify the aircraft's route and status by adjusting parameters such as thrust, steering, and attitude.
The primary objectives of Guidance, Navigation, and Control (GNC) systems are to ensure accurate navigation, precise guidance, and effective control of vehicles. These systems aim to achieve reliable pathfinding, maintain vehicle stability, and control the vehicle's trajectory for safe and precise mission execution, while also optimizing performance and efficiency in dynamic environments.