Introduction -

Ascent Phase Flight Control

Ascent Phase Flight Control refers to the control system used to guide a rocket during its initial launch phase, from the ground up to the point where it reaches space. This phase is critical because it involves managing the rocket's direction, speed, and stability to ensure it stays on its planned path and doesn't deviate, which could result in mission failure.

Sliding Mode Control

Sliding Mode Control (SMC) is a type of control method used to manage and stabilize systems that are complex and have uncertain parameters. It works by making the system's behavior "slide" along a predetermined path or surface, correcting any deviations quickly and effectively. In the context of Ascent Phase Flight Control, SMC can be used to precisely control the rocket's movement even in the presence of unpredictable factors like wind or minor mechanical issues, ensuring a smoother and more reliable ascent.

Objectives & Key Results

Objectives For 6-DoF ascent phase rocket flight

Develop a 6-DoF simulator for the ascent phase of rocket flight, considering the following aspects:

• [x] Rotation dynamics (Euler's equation for rigid body dynamics, Quaternion equation)
• [x] Translation dynamics (Newton's law)
• [x] Constant Earth gravity (Flat Earth model is acceptable) ➡️ Using a more accurate mode of **WGS84 Gravity Model (**assumption of a geocentric equipotential ellipsoid of revolution)
• [x] Simple Earth atmosphere ➡️ Using a more accurate mode of ISA Atmosphere model
• [x] Simple aerodynamic model ( ☑️ Currently using Lift and Drag aerodynamic model ➡️ A modified version of Axial force and Normal force aerodynamic model 🚧 ) ⁉️ We assume the rocket design to be cylindrical, meaning it is symmetric in terms of force and inertia about the y and z axes of the body frame. Additionally, we neglect the aerodynamic forces on the rocket fins and the aerodynamic drag resulting from the rocket's own rotation.
• [x] Isp and thrust change with pressure
• [x] Second-order actuator model ( 🚩 I still need some research on this topic and it will not be included in the demonstration model on Monday)

Key Results For 6-DoF ascent phase rocket flight

• [x] Reference sources or principles for each model in the 6-DoF simulator
• [x] Complete rocket dynamic function and build into Simulink model

Objectives For Sliding Mode Control