vault backup: 2025-02-03 08:29:48

OneNote/OSD/Research/Books.md

@@ -0,0 +1,3 @@
+1. Amir MY, Abbas V (2010) Modeling and neural control of quadcopter helicopter: MATLAB-SIMULINK based modeling, simulation and neural control of quadcopter helicopter. LAP LAMBERT Academic Publishing, Germany
+2. PutroIE(2011)Modelingandcontrolsimulationforautonomousquadcopter:quadcopternonlinearmodelingand control simulation using Matlab/Simulink environment. LAP Lambert Academic Publishing
+3. Norris D (2014) Build your own quadcopter: power up your designs with the Parallax Elev-8. McGraw-Hill Edu- cation, New York

OneNote/OSD/Research/ESD.md

@@ -0,0 +1,324 @@
+[Notes to ESD essentials by TI](https://training.ti.com/esd-essentials-what-esd?context=1136983-1139548-1135647)
+
+  
+
+ESD - Electrostatic discharge
+
+This happens when you're getting charged up positively and touch a conductor.
+
+Large voltages can be generated that can damage Ics.
+
+  
+
+ESD diodes can be used to direct those ESD-currents into GND, before they can reach the Ics
+
+  
+![Circuit with ESD Protection 
+Interface 
+Connector 
+ESD 
+Diode 
+ESD Essentials 
+System 
+Circuitry ](Exported%20image%2020231126172008-0.png)  
+
+# Chapter 2 - ESD Working Voltage
+
+Also known as Reverse Standoff Voltage
+
+  
+![Working Voltage vs. Breakdown Voltage 
+ESD 
+ESD I-v Plot 
+e tials 
+ESD 
+Diode 
+0:18 
+Protected 
+Circuitry 
+0:55 
+16 
+14 
+12 
+10 
+4 
+2 
+0 1 2 3 4 5 6 7 8 9 10 11 
+voltage (V) ](Exported%20image%2020231126172008-1.png)  
+
+Indicated by red: BreakDown Voltage. Any voltage larger than this will make the diode conductive.
+
+  
+![(Λ) αβηΙ0Λ 
+ΥΙΙΟΙ 
+νηι•ο 
+ΊΙΙ' Ό 
+νιΙΙΟΙ 
+ΥΙΙΙΟΟΙ 
+Λ-Ι asa 
+a6ellO/\ uMOP>1eaJ8 Θ6ηΙOΛ 611!ΥΙ0Μ ](Exported%20image%2020231126172008-2.png)  
+
+The signal level, which is used normally should be below VRWM --> like that we have below 10 nA leakage current.
+
+  
+
+The working voltage of the diode you choose should be slightly higher than the largest signal.
+
+  
+![Bidirectional vs. Unidirectional ESD 
+Configuration 
+Bidirectional 
+1/0 
+Functional Diagram 
+- GND 
+Has a symmetric positive and negative 
+breakdown voltage 
+Definition 
+Can be used for interfaces with both 
+positive and/or negative voltage ranges 
+Supported Interfaces 
+(all interfaces) 
+In I-channel ESD bidirectional ESD, any pin 
+can be the I/O and any pin can be the 
+ground 
+ESD Essentials 
+Unidirectional 
+1/0 
+GND 
+Has a positive breakdown voltage but 
+breaks down almost immediately in the 
+negative direction 
+Can only be used for interfaces that only 
+have a positive voltage range 
+Digital inputs, USB, HDMI and other 
+positive signal interfaces 
+Has better negative clamping performance 
+than bidirectional diodes since the negative 
+breakdown voltage is lower. ](Exported%20image%2020231126172008-3.png)  
+
+# IEC 610000-4-2 ESD Rating
+
+  
+![ESD Standard: IEC 61000-4-2 
+ESO s 
+IEC 61000-4-2 ESD 
+*Designed for real world 
+applications 
+ESD Essentials 
+61000-4-2 
+HBM 
+20 
+40 
+60 
+Time (ns) 
+80 
+100 
+TEXAS INSTRUMENTS ](Exported%20image%2020231126172008-4.png)  
+  
+
+## Human Body Model (HBM) ESD
+
+This is used to estimat the manufacturing, assembly and shipping. Not for the final use!
+
+  
+
+## Charge Device Model (CDM) ESD
+
+ESD discharge through charged device into ground. Also only Manufacturing, assembly and shipping.
+
+  
+
+## IEC 61000-4-2
+
+This is the model that simulates the final use by the user. There are 4 Levels and devices next to interface connectors should use at least level 4.
+
+  
+![Look for the IEC 61000-4-2 Rating 
+IEC 61000-4-2 
+Level 
+1 
+2 
+3 
+4 
+E D Ratin s 
+Contact 
+Voltage 
+2kV 
+6kV 
+8kV 
+Air Gap 
+Voltage 
+2kV 
+4kV 
+8kV 
+15kV 
+6.2 
+V(ESO) 
+Humm (HBM). ANSVESDA/JEOEC 
+Chat%d-device rncxlel (COM). JEDEC 
+CIO' 
+6 Contact Discharge 
+Discharge 
+ESD Essentials 
+VALUE 
+*15000 
+*15000 ](Exported%20image%2020231126172008-5.png)  
+
+# Clamping Voltage
+
+This is the important measure, because it describes the voltage protection capability of the clamping diode.
+
+![Common Misconception regarding IEC 
+Interface 
+Connector 
+ESD 
+Diode 
+IEC 610004-2 Rating 
+measures the robustness of the 
+diode 
+(ex: 8kV contact Il 5kV air gap) 
+System 
+Circuitry 
+be exposed to. 
+ESD Esse 
+v 
+ESD clamping voltage 
+rating measures how well the 
+ESD diode will protect 
+system circuitry ](Exported%20image%2020231126172008-6.png)  
+![Clamping Voltage on the T LP Plot 
+— 12 
+ESD Essentials 
+22A 
+ESD 
+15.5V 
+Diode 
+Minimize RDYN to provide 
+better clamping voltage 
+and protection 
+18 
+10 
+2 
+Transmission Line Pulse Plot 
+nds 
+0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 
+Voltage (V) ](Exported%20image%2020231126172008-7.png)  
+
+Depending on the ESD strike a different current is shunted through the diode. This results in a remaining voltage drop, which the system circuitry will be exposed to. That is the voltage that can still damage our system. --> select diode according to max voltage that system can survive.
+
+# Parasitic Capacitance
+
+![ESD Junction Capacitance 
+Interface Signal 
+ESD Esse 
+Protected 
+Circuitry 
+N -type 
+P-type ](Exported%20image%2020231126172008-8.png)
+
+Because of the physics the diode can be modeled as a capacitor. Hence it will influence the circuit during normal operation.
+
+  
+
+If parasitic capacitance is high it can influence the signal:
+
+![Capacitance Effect on Signal Integrity 
+Input Interface 
+Signal 
+ESD 
+Diode 
+ESD Essen—. 
+Signal 
+capacitance 
+interference 
+Protected 
+Circuitry ](Exported%20image%2020231126172008-9.png)
+
+This means for a highspeed signal it is extremely important that the parasitic capacitance is small.
+
+  
+
+General overview:
+
+![Capacitance Recommendations 
+ESD Typical 
+Tl Recommended 
+Interface 
+GPIO 
+Pushbutton 
+Audio 
+USB 2.0 
+USB 3.0 
+USB 3.1 Gen 2 
+HDMI 1.4 
+HDMI 2.0 
+Ethernet 
+Antenna 
+4-20mA Loop 
+Suggested 
+Capacitance (C') 
+<30pF 
+<30pF 
+<10pF 
+<2.5PF 
+<0.5pF 
+<O.3pF 
+<O.7PF 
+<0.5pF 
+<5pF 
+<O.2pF 
+<80pF 
+Device ](Exported%20image%2020231126172008-10.png)  
+  
+
+# ESD Protection selection
+
+![ESD Selection Steps 
+Was thi* 
+ESD Esse tlals 
+1) 
+2) 
+3) 
+4) 
+5) 
+Quantify the signal range of your signal/power interface to 
+determine the ESD diode's working voltage. 
+Decide whether a unidirectional or bidirectional configuration 
+is preferred. 
+Decide the maximum capacitance can be accepted for the 
+interface. 
+Determine what TLP voltage the system fails at to determine 
+the necessary clamping voltage of the diode. 
+Ensure that the diode exceeds IEC 61000-4-2 level 4. ](Exported%20image%2020231126172008-11.png)  
+![Step 4: Determine TLP Clamping Voltage 
+ESD Essentials 
+<16V 
+<16V 
+Battery 
+Charger 
+Fails: 20V TLP 
+USB 2.0 
+Switch 
+Fails: 16V TLP 
+Bidirectional 
+Any 
+<20Vat 16A 
+TLP 
+>3.6v• 
+Bidirectional 
+<2.5PF 
+<16V at 16A 
+TLP 
+GND 
+USB 
+Receptacle 
+Polarity 
+Configuration 
+Capacitance 
+Clamping 
+Voltage 
+IEC 61000-4-2 
+Rating 
+TLP failure voltage is NOT the same as absolute 
+maximum voltage. Absolute maximum voltage is a 
+DC voltage while TLP is a 100ns transient. ](Exported%20image%2020231126172008-12.png)

OneNote/OSD/Research/GNSS.md

@@ -0,0 +1,13 @@
+Can we use AI to improve GNSS signals?
+
+  
+
+[https://insidegnss.com/what-are-the-roles-of-artificial-intelligence-and-machine-learning-in-gnss-positioning/](https://insidegnss.com/what-are-the-roles-of-artificial-intelligence-and-machine-learning-in-gnss-positioning/)
+
+  
+
+--> use semantic image comparison with database.
+
+--> multipath detection
+
+--> better sensor fusion

OneNote/OSD/Research/Helicopter.md

@@ -0,0 +1,112 @@
+> [!caution] This page contained a drawing which was not converted.  
+
+Tip speed should not exceed 200 m/s.
+
+For us that is roughly 6400 rpm.
+
+Formula: 200*60/D/pi
+
+- Rotor size and max weight are first things to consider.
+- Normalizing Entities to compare between models --> make dimensionless
+    
+    - Non-dimensional induced velocity
+        
+        - ![Exported image](Exported%20image%2020231126172013-0.png)
+    - Thrust coefficient
+        
+        - ![Α ](Exported%20image%2020231126172013-1.png)
+        - VT is tip speed of blade
+        - Thrust is divided by dynamic pressure times area --> gives Force [N]
+    - Combined:
+        
+        - ![ст 
+            Ст — 411 ](Exported%20image%2020231126172013-2.png)
+- Power overview:
+    
+    - Induced Power is major part of power during hover
+    - Power to overcome blade drag PO
+    - ==Solidity== of rotor:
+        
+        - ![Exported image](Exported%20image%2020231126172013-3.png)
+    - Skin friction drag:
+        
+        - ![Exported image](Exported%20image%2020231126172013-4.png)
+          
+          
+        - ![Exported image](Exported%20image%2020231126172013-5.png)
+    - Rotor efficiency: M = Pi/PO --> Figure of Merit
+        
+        - ![- (CT)3/2 
+            2 ](Exported%20image%2020231126172013-6.png)
+        - ki is induced power factor because of a variation in induced velocity
+
+  
+  
+
+# Blade Aerodynamics
+
+- ![dL 
+    Disc Plane 
+    Figure 3 A 
+    Blade Section 
+    Blade section flow conditions in vertical flight ](Exported%20image%2020231126172013-7.png)
+- Angles:
+    
+    - Inflow Angle (small angle approx)
+    - ![Exported image](Exported%20image%2020231126172013-8.png)
+    - Theta: pitch control by pilot
+    - Alpha: angle of attack seen by blade
+- Aerodynamic forces
+    
+    - Lift and Drag
+        
+        - ![dL=-pU2.cdr.CL 
+            dD=-pU2.cdr.CD ](Exported%20image%2020231126172013-9.png)
+    - Thrust
+        
+        - ![Exported image](Exported%20image%2020231126172013-10.png)
+    - Blade Torque
+        
+        - ![Exported image](Exported%20image%2020231126172013-11.png)
+    - Thrust coefficient with a linear twist blade and the assumption of no stall and no compressibility
+        
+        - ![075% λ ](Exported%20image%2020231126172013-12.png)
+          
+        - ![Exported image](Exported%20image%2020231126172013-13.png)
+        - Lambda: inflow factor
+            
+            - ![Exported image](Exported%20image%2020231126172013-14.png)
+            - Relating the inflow factor to momentum theory (see above)
+                
+                - ![CT = sa 
+                    3 
+                    2 
+                    CT 
+                    2 ](Exported%20image%2020231126172013-15.png)
+            - Relationship between inflow factor and pitch setting
+                
+                - ![Exported image](Exported%20image%2020231126172013-16.png)
+    - Why are blades twisted? My assumption is that the angle of attack seen by the blade depends on the wind speed it experiences. This in turn, depends on the radius and the angular velocity of the blade. The closer you are at the hub, the larger is the inflow angle and thus the smaller is the angle of attack. That means if we twist the blade and add additional aoa close to the hub and remove aoa where the speed is high, we will have more lift in total and not have a stalling condition somewhere and not at other places.
+
+  
+
+# Flapping, Feathering & Lead-Lag
+
+- Coriolis Force induces lag
+    
+    - ![In Newtonian mechanics the equation ot motion tor an object in an ineäial reference tram 
+        F = ma 
+        where F is the vector sum ot the physical forces acting on the object, m is the mass ot tr 
+        Transforming this equation to a reference frame rotating about a fixed axis through the orl 
+        F m — x — 2mu x — mu x x ) = ma' 
+        where 
+        F is the vector sum of the physical torces acting on the object 
+        is the angular velocity, of the rotating reference frame relative to the inertial trame 
+        v' is the velocity relative to the rotating reference frame 
+        r' is the position vector of the object relative to the rotating reference frame 
+        a' is the acceleration relative to the rotating reference frame 
+        The fictitious forces as they are perceived in the rotating trame act as additional forces thi 
+        • Euler torce —m— x 
+        • Coriolis torce —2rn(w x v') 
+        • centrifugal force —mu x (w x r' ](Exported%20image%2020231126172013-17.png)
+-

OneNote/OSD/Research/PCB Design.md

@@ -0,0 +1 @@
+[Great article about Ground return paths and mixed signal pcbs](https://www.maximintegrated.com/en/design/technical-documents/tutorials/5/5450.html)

OneNote/OSD/Research/Quan Quan – Mulicopter Design and Control.md

@@ -0,0 +1,5 @@
+# Ideas
+
+- Use large coaxial for thrust (collective) and pitch only and add small rotors on wings for roll.
+    
+    -