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Explore the world of quadcopters step by step, from the basics of flight maneuvers to advanced control algorithms. Learn about altitude control, IMUs, PID algorithms, and more. Discover the potential for aerial photography, delivery systems, and search and rescue missions. Dive into the future with nonlinear control, accurate estimators, SLAM, and motion planning. Whether you're a beginner or an enthusiast, this guide will take you through the essentials and beyond.
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Quadcopters A CEV Talk
4 movements • Altitude • Up • Down • Roll • Left • Right • Pitch • Front • Back • Yaw • Heading
Altitude • Hover
Altitude • Up
Altitude • Down
Quick question Correct Wrong
However • Scaling up,
4 rotors • 4 rotors harder to control than one
Nevertheless • Mechanical Simplicity + Electronic Stabilization win
Perks • Less stable = learn more control theory. • Less kinetic energy per motor(rotor). You wont lose your fingers.
Stability: The Notion Mind Sense Take action
Angle calculation: Accelerometer • Inclination from an axis can be calculated using the component of gravity along that particular axis.
Angle calculation: Gyroscope • Gyroscopes provide angular rate in degrees per second. • The angle with a certain axis can be calculated by integrating the angular velocity with respect to that axis over the sampling period.
IMUs are not perfect! • Accelerometers: When in motion, the acceleration of the robot affects the acceleration measured by the accelerometer. • Gyroscopes : Due to manufacturing limitations, signal drift often accompanies MEMS gyros. When integrated over time, this drift leads to considerable error.
Complementary filter • Simplest filter for IMUs • Corrects Gyro drift by including a certain component of angle measured by the accelerometer in angle measurement Angle= 0.98*(Gyroscope Angle) + 0.02*(Accelerometer angle)
Proportional-Integral-Derivative : An Intuition • Proportional term generates output based on error • Integral term generates output based on bias in error • Derivative term generates output based on speed of error variation Mathematical procedures to tune PID constants (very hard work): -- Root locus method -- Bode plots -- Nyquist Criterion -- Zeigler Nicols Algorithm Method which usually works: -- Trial and Error (video)
Inside The Controller Control signals for ESC, which will in turn command motors Set point PID error Computed Angles Measured Angular rates And acceleration Filtering and Data fusion
The Closed Loop Controller Quadcopter dynamics Sensors
Onward we fly… • Quads in aerial photography, delivery systems, search and rescue…
Onward we fly… • Better (Nonlinear) Control • Accurate estimators • SLAM • Motion Planning
Better Control • Non linear control (V) • Robust control • Adaptive control • Stochastic control
Accurate Estimators • Implementing Extended Kalman filter • Third order stochastic filter • Multi state constraint Kalman filter for vision aided navigation
So Far So Good • Hardware • Stability • Movement • Interaction?
Quad’s eye view • What does the world look like? [MAPPING] • Where am I? [LOCALIZATION] • A chicken and Egg problem