diff --git a/Article_Scientifique/main.tex b/Article_Scientifique/main.tex index d94ae35..6a3b156 100644 --- a/Article_Scientifique/main.tex +++ b/Article_Scientifique/main.tex @@ -1,6 +1,7 @@ \documentclass[conference]{IEEEtran} \IEEEoverridecommandlockouts % The preceding line is only needed to identify funding in the first footnote. If that is unneeded, please comment it out. +\usepackage[UKenglish]{babel} \usepackage{cite} \usepackage{amsmath,amssymb,amsfonts} \usepackage{algorithmic} @@ -107,7 +108,7 @@ they often introduce vulnerabilities. Open-source projects, in particular, must developers with the need to secure the vehicle. We also argue the need for general public's safety when it comes to these bikes, as it could be a danger to the traffic. - This is especially true when it comes to vehicules carrying a substantial load. This needs to be considered by the MAD, + This is especially true when it comes to vehicles carrying a substantial load. This needs to be considered by the MAD, where their responsibility and control begins and ends. Should there be a difference between the firmware loaded on a product from the MAD than what is publicly available? @@ -118,7 +119,7 @@ We also argue the need for general public's safety when it comes to these bikes, \label{sec:relatedwork} \subsection{Modeling of BLDC Motor} -The electromechanical model of a BLDC (Brushless DC) motor is foundational for understanding its behavior under different control +The electromechanical model of a BLDC (Brushless DC) motor is foundational for understanding its behaviour under different control schemes. BLDC motors are categorized by their back-electromotive force (back-EMF) waveform: trapezoidal or sinusoidal. This distinction is crucial, as the trapezoidal shape inherently leads to torque ripple when the supplied phase currents are not perfectly aligned, directly influencing the choice and effectiveness of the control strategy @@ -128,7 +129,7 @@ T_e = \frac{e_a i_a + e_b i_b + e_c i_c}{\omega_m} \] where \( e_x \) is the back-EMF and \( i_x \) is the phase current \cite{li_quantitative_2019}. The classical d-q reference frame model, ideal for sinusoidal machines, is less suitable for trapezoidal BLDC motors because it assumes -sinusoidal flux distribution. Phase-variable modeling in the natural (abc) frame is therefore more appropriate, as it +sinusoidal flux distribution. Phase-variable modelling in the natural (abc) frame is therefore more appropriate, as it directly accounts for the non-sinusoidal, trapezoidal nature of the back-EMF and the associated harmonics \cite{mohammd_taher_new_2021}. @@ -137,7 +138,7 @@ directly accounts for the non-sinusoidal, trapezoidal nature of the back-EMF and % 120 electrical degrees. Trapezoidal commutation, or Six-Step control, uses bipolar conduction, with two motor phases conducting at any time and current commutation occurring every 120 electrical degrees \cite{gieras_modern_2023}. As commutation depends on rotor -position, Six-Step control requires either position sensors (e.g. Hall sensors, encoders, or resolvers) or sensorless +position, Six-Step control requires either position sensors (e.g. Hall sensors, encoders, or resolvers) or sensor-less estimation based on back-EMF detection or observers \cite{gieras_modern_2023, gasc_conception_2004}. This method is renowned for its simplicity of implementation and low hardware cost \cite{bhatiya_bldc_2024}. It enables effective torque control but introduces significant torque ripple during commutation events, especially under high load @@ -233,13 +234,6 @@ PID-based (Proportional-Integral-Derivative) control strategy combined with dist assistance based on system dynamics. -% ************************************** LOW TECH SIX STEP CONTROL ***************************************************** - - -\section{Hardware-Based Six-Step Commutation Controller} -\label{sec:sixstep} - - % ************************************** FIELD ORIENTED CONTROL ***************************************************** \section{STM32-Based Field-Oriented Control Motor Drive} @@ -371,7 +365,7 @@ The main modifications performed on the schematic were: \end{itemize} Special attention was given to the routing of critical control signals, especially the PWM outputs used for -motor commutation and the analog signals used for current sensing. +motor commutation and the analogue signals used for current sensing. After the modifications, the schematic was verified using the KiCad Electrical Rule Check (ERC). No electrical errors were detected during this verification step, which validated the consistency of the schematic before @@ -402,6 +396,42 @@ Once the routing is completed, the board will be manufactured and tested using t STM32L476 tile. +% ************************************** LOW TECH SIX STEP CONTROL ***************************************************** + +\section{Hardware-Based Six-Step Commutation Controller} +\label{sec:sixstep} + +The basis of this section is the replacement of components who are highly complex, technical and/or are dependant on global supply chains to manufacture. An additional goal is, as for the preceding section, to make a repairable, reliable and manufacturable circuit, this time using these more basic components, based on open-source principles. The controller needs to be performant enough to drive one of the two electric motors used on the LaMAD (La Manufacture Autonome Décentralisée) bicycle cargo trailer. %ref moteur qu'utilise lamad + + +\subsection{AIME and other SC-facilities capabilities} +The most challenging part of this section is the replacement of semiconductor parts. + + +\subsection{Replacing an IC} + +Replacing the IC of a motor controller requires using traditional logic gates. This approach is + +\subsection{Power components} + + +\subsection{Clock} + +To calculate the maximum rotation speed, we take the worst conditions of the motor used in the MAD cargo bike; 50 km/h\footnote{http://www.mxusebikekit.com/pro\_info.asp?Pid=25} with a 50 cm wheel\footnote{http://www.mxusebikekit.com/pro\_info.asp?Pid=25}\footnote{https://veloma.org/2022/10/05/la-charrette-version-montagne-ou-comment-transporter-250kg-a-velo-par-monts-et-par-vaux/} (not measured, assumed from the images and the motor specifications). + +\begin{equation*} + \omega=\frac{v}{\pi d}=\frac{50\cdot 10^3m/h\cdot\frac{1}{60}h/min}{3,14\cdot 50\cdot 10^{-2}m}=530\ rpm +\end{equation*} + +The motor being a three-phase brushless motor, the switching speed needs to be + + + + + + + + % ************************************** SOFTWARE AND CONNECTIVITY ***************************************************** \section{Software and Connectivity} @@ -428,8 +458,8 @@ bluetooth module supporting BLE will be the easiest solution. Preferably a modul Bluetooth could be a vulnerability to a VESC if it is to be used as a controller in real-time, as the controller could be jammed. Our test with the Flipper Zero shows the disfunctionnality of Bluetooth with different use cases. We experienced with the jamming of a bluetooth speaker that the music completely stopped. It could also be investigated -how the connection to the VESC could be modified using the vesc tool. We will touch more on the accessability of the -code within the vesc tool sooner. +how the connection to the VESC could be modified using the vesc tool. We will touch more on the accessibility of the +code within the VESC tool sooner. \subsection{Setup of BT-connection with VESC} The setup consisted of a main PC/controller, HC-05 Bluetooth module, ESP8266 µ-controller, STM32 Discovery µ-controller, PC with VESC-tool aswell as a \textit{FlipperZero}. Our plan of action consisted of flashing the Discovery-card with code for then to read this code via UART to the ESP8266 which was connected to the BT-module. The BT-module would then send packets to the PC. This PC would then act as read/write to read the code having been flashed on the Discovery. Full-band jamming would then be achieved by the implementation of the \textit{FlipperZero} disrupting any transfer of code from PC1 to PC2. @@ -554,7 +584,7 @@ This documentation could be as simple as referencing the relevant parts of the l \subsubsection{Proposed Solution} This risk could be patched by developing a VESC application for the VESC controller or using a binary. This is a solution which is less open source, but which is make unlawful use of the material harder. The application could be -created using C and use an algorithm known by the MAD in order to securise the access to someone to change the parameters +created using C and use an algorithm known by the MAD in order to secure the access to someone to change the parameters only if they are the MAD certified personnel. This encryption would preferably be reduced to the most essential settings in order to align with what our impression of the philosophy of the MAD would be. @@ -573,11 +603,10 @@ by using an esp8622 that we had as well. We propose that the next group has acce beginning, as well as a motor we could control. This could be in cooperation with the MAD, as the MAD could propose some models they're interested in. -We also found that the information on the VESC is scattered around the internet. The ressources is also sometimes -based on a debian-based linux system which adds more work for someone using another distribution of linux. This could -hinder the implementation facility for new users. We struggeled particularly with the Qt packages for positioning and -gamepad. We would therefore recommend the use of a debian-based linux system for the computer working with the VESC -for the the MAD associates. +We also found that the information on the VESC is scattered around the internet. The resources is also sometimes +based on a Debian-based Linux system which adds more work for someone using another distribution of linux. This could +hinder the implementation facility for new users. We struggled particularly with the Qt packages for positioning and +game pad. We would therefore recommend the use of a Debian-based Linux system for the computer working with the VESC for the MAD associates. % ************************************ DYNAMIC MODELLING *************************************************************** @@ -837,24 +866,24 @@ in development. As a final note, this proved to be a project which could easily be developed into several different projects in different fields. Some projects could be continued later on as a different PIR subject, other could be proposed to -later years in different spesialisations like TLS SEC, ESPE. Our thoughts on the following projects that could be +later years in different specialisations like TLS SEC, ESPE. Our thoughts on the following projects that could be explored are the following. The fabrication line for electronics is globalised. This is okay in a stable world, but it could be a problem in a world -full of instability, be it war, blockages, or tarifs. The idea of opening a spesialisation in cooperation with AIME came +full of instability, be it war, blockages, or tarifs. The idea of opening a specialisation in cooperation with AIME came up as an idea. -For TLS SEC the subject could be the design for a fitting mechanism to restrict certain priveligies to certified +For TLS SEC the subject could be the design for a fitting mechanism to restrict certain privileges to certified personnel that could be used in the C programming language. Later down the line we could also see the possibility to analyse the Bluetooth frames in order to manipulate them in order to change important parameters. -The continuation on the PCB could be a subject fitting an ESPE spesialisation. +The continuation on the PCB could be a subject fitting an ESPE specialisation. -The proposition of and supply of a vesc system to play with and troubleshoot could be a good rule of thumb, which +The proposition of and supply of a VESC system to play with and troubleshoot could be a good rule of thumb, which allows for a quicker start and gives among other things an idea of the budget and the supply line used by a entity in the sector. Proposing a visit could also be one way to familiarise students with the association. -What should be a clear conclusion from our test with the jammer is that a controlles based on Bluetooth alone should be +What should be a clear conclusion from our test with the jammer is that a controller based on Bluetooth alone should be avoided when possible and practical. Examples where this could be relevant include electric skateboards, as cables could impose a tripping hazard. There, an encapsulation of an encrypted control frame could be an thought.