Picked from the software, topic, and level of “Class Quadrotor Sliding Mode Control Theory #3: Sliding Mode Control Theory: Sliding Surface and Control Law”.
At most one email a week. Unfollow anytime with one click.
Transcript
The full narration of this video. The current sentence is highlighted while the video plays; click any sentence to jump there.
Show transcript
Introduction
This is the final result, the sliding mode control phase plane, where the system is forced to slide towards the surface line and then slide over it towards the target, even though it is continuously disturbed. We also see the dark side, chattering, and how to tame it. Let's get started. Hello, welcome to episode three of the quadrotor control series with sliding mode control. Sliding mode control or SMC is a robust control method. It only needs to know the upper bound of the disturbance, not the exact value. Before using it on the quadrotor, let's first study the concept on the simplest system. X2 equals U plus disturbance. Create a file named theory underscore smc.py.
Step 1: Sliding Surface & Control Law
The system is X2 equals U plus D, with a desinusoidal disturbance of amplitude 1.5. The sliding surface S equals the derivative of the error plus lambda times the error. If S is zero, the error decays exponentially on its own. The control law is minus lambda times the velocity, minus k times the sign of S. With K3 greater than the disturbance bound of 1.5, S multiplied by the derivative of S is always negative. So the system will definitely reach S equals zero and stay there. The simulation function can use pure sign or the saturated version with baun from the layer.
Step 2: Reaching Time & Chattering
Run for both versions. With sign, the system reaches the sliding surface S equals zero at 1.8 seconds, faster than the theoretical bound of 2.67 seconds, and X finally ends up almost at zero, 0.00035. But the change in the control signal is very large, 2.77 per step. With baun from the layer, the control signal is a thousand times smoother, with a slightly higher final X value, 0.0085. This is the classic compromise of SMC.
Step 3: Phase Plane & Boundary Layer
Let's take a look at the graph. The phase plane shows two phases. Reaching, as the system moves from the initial point to the dashed line sliding surface Then sliding, as the system slides along the line towards the zero point, regardless of the disturbances. The middle graph shows X approaching 0. The right graph is the control signal zoom. The sign switching between positive and negative is very fast, This is the catering that can damage the motor, while the smooth layer version. Done.
Done!
We have already understood the theory of sliding mode control, sliding surface, control law, stability conditions, reaching and sliding phases time reaching, as well as catering and baun from the layer. In the next episode, we will apply SMC to the quadrotor. Currently working on a thesis, dissertation, or research in the field of control systems, drones, and UAVs. Cerdas Inovasi Digital helps with the implementation of control systems, from the 6 degrees of freedom quadrotor modeling, PI is upgraded, sliding mode control, until the disturbance observer for wind, as well as opening a Python programming course for electrical and mechatronic engineering. Want to master the entire series, From the quadrotor model to 3D trajectory testing with wind? All 6 episodes, Complete with a step-by-step PDF guide and source code, available for premium tutorial subscribers. Subscribe starting at Rp69.000 per month, save 28% with the 12-month package, or pay once Rp999.000 for lifetime access. Want just one class? Buy the single class with lifetime access. Subscribe now on the premium page cerdasinovasidigital.com. Contact our WhatsApp, or visit cerdasinovasidigital.com. Thank you for watching, see you in the next episode.
Ask the class material
Type a question or keyword; we find the part of this episode that explains it and jump the video there.
My notes
Notes are saved with the current video time and are only visible to you.
Questions & answers
Stuck on a step? Ask here; the instructor and other learners can answer.
No questions yet.
Your instructor
Cerdas Inovasi Digital Team
Software developers, BIM & 3D engineers, and AI practitioners
53 video classes1,281 episodes
We build software, BIM models, games and AI automations for clients every day, and turn that hands-on work into step-by-step classes: every step is shown on screen and comes with a PDF guide you can keep.
