diff --git a/Article_Scientifique/main.tex b/Article_Scientifique/main.tex index 9de8141..c82c15d 100644 --- a/Article_Scientifique/main.tex +++ b/Article_Scientifique/main.tex @@ -5,7 +5,7 @@ \usepackage{amsmath,amssymb,amsfonts} \usepackage{algorithmic} \usepackage{url} -\usepackage{hyperref} +\usepackage[hidelinks]{hyperref} \usepackage{placeins} \usepackage{siunitx} \usepackage{graphicx} @@ -90,7 +90,7 @@ bikes while significantly improving repairability. \end{abstract} \begin{IEEEkeywords} -VESC Project, Brushless DC motor, Field Oriented Control, Trapezoidal commutation, Low-Tech, e-bike. +VESC, Brushless DC motor, Field Oriented Control, Trapezoidal commutation, Low-Tech, PID-Control. \end{IEEEkeywords} \section{Introduction} @@ -114,7 +114,7 @@ We also argue the need for general public's safety when it comes to these bikes, \section{Related Work} \subsection{Modeling of BLDC Motor} -The electromechanical model of a BLDC motor is foundational for understanding its behavior under different control +The electromechanical model of a BLDC (Brushless DC) motor is foundational for understanding its behavior 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 @@ -185,6 +185,7 @@ repairability constraints. To date, researchers have not addressed the challenge be locally fabricated, repaired with standard components, and secured against unauthorised wireless access requirements that are critical for decentralised, community-operated fleets. + \section{Aim and Research Objectives} This work presents the design and implementation of a motor control system for electric bicycles and cargo transport applications developed within the context of the Manufacture Autonome Décentralisée (MAD) initiative at INSA Toulouse. @@ -541,6 +542,41 @@ equilibrium position, demonstrating stable closed-loop behaviour and satisfactor \end{figure} \subsubsection{Experimental Load Characterization} +Experimental tests were conducted on flat terrain in order to evaluate the influence of mechanical load on the motor +current consumption of the cargo cart system. The system was powered using a \SI{48}{\volt} battery pack. + +Current measurements were acquired using an Analog Discovery 2 connected to a computer running the WaveForms software +environment. A current clamp probe was used to measure the motor current, and the signals were sampled at +\SI{1}{\kilo\hertz}. + +During each test, the throttle command was set to its maximum value in order to produce the highest possible +acceleration. Once the maximum speed was reached, the motor current naturally decreased and stabilised as the motor +only compensated for rolling resistance and friction effects. + +Three loading conditions were investigated corresponding approximately to one, two, and three passengers inside the +cargo cart. The motor current measured during these experiments is shown in Fig.~\ref{fig:motor-currents}. + +\begin{figure}[!h] + \centering + \includegraphics[width=\linewidth]{./Figures/Motor_currents.png} + \caption{Measured motor current under three loading conditions.} + \label{fig:motor-currents} +\end{figure} + +The results show a significant current peak during the acceleration phase, reaching the controller limit of +approximately \SI{25}{\ampere}. After this transient phase, the current decreases and converges toward a lower +steady-state value corresponding mainly to friction and resistive force compensation. + +As expected, higher loading conditions resulted in higher steady-state current consumption, indicating an increase in +the required motor torque. In addition, the duration during which the current remained close to the maximum controller +limit also increased with heavier loads, reflecting the longer acceleration time required to reach steady-state +operation. +These variations are mainly attributed to terrain irregularities, throttle response fluctuations, and limitations +associated with the measurement setup and current probe acquisition chain. + +However, due to the absence of direct velocity measurements during the experiments, only qualitative observations could +be extracted from these tests. Consequently, a precise estimation of dynamic friction parameters and energy efficiency +could not be achieved. \subsection{FOC Controller Validation}