If a corner has a big enough radius, the car can negotiate without slowing down. This is then done backward for braking zones and forward for corners exit and straight sections. In a given point, say for example the apex of a corner (which corresponds to the point of minimum radius) the solver calculates, basing on the performance envelope, the magnitude of the acceleration the car can achieve and, from there, the speed. The elevation profile is also considered in terms of its effects in acceleration phases. In particular, the matrix giving the corner radius in each point of the track is calculated basing on logged data (time, speed and lateral acceleration or, if available, basing on GPS data). The track itself is defined by many small portions of a certain length, with a corner radius and an altitude input by the user.
In an acceleration phase, the tool considers the resisting forces given by aerodynamic drag, rolling resistance and, if cornering, by tires slip.
TIME MATLAB 2012 FULL
Starting from there, the solver proceeds backward (using the full braking potential of the car, when possible, or a portion of it when the car is already cornering) and forward (same as for braking, but now, beside grip, the other deciding factor is the power the engine can transmit to the driven wheels).
TIME MATLAB 2012 PLUS
No combined (lateral plus longitudinal) situations are explicitly simulated in deriving the performance envelope.įirst of all, the maximum speed the car can achieve at the apex of each corner is calculated. To do this, the lateral and longitudinal available grip is combined as an ellipse. Once the performance envelope has been calculated in both lateral and longitudinal direction, the solver uses it to calculate the speed of the car in each point of the track. More on this later.įor now, anyway, this means that CG height always stays constant and ride heights are not mapped, with the aerodynamics being described by one single coefficient for downforce, one for drag and one for aerodynamic balance.
TIME MATLAB 2012 DRIVER
Suspensions are for now considered only as the driver for the final lateral load transfer distribution between front and rear axles. To do this, a 4 wheels vehicle model is used, where each tire characteristics can be specified, together with the main geometrical parameters of the vehicle (wheelbase, track widths), masses (overall vehicle weight, front mass distribution), aerodynamic (downforce and aerodynamic balance), CG height, brake balance and the portion of the engine torque transmitted to the rear wheels. The latter, is considered once for braking and once analyzing acceleration. The working principles remained the same.īasing on user input, the tool derives a performance envelope (or map, if you want), which is basically a g-g-V diagram (achievable acceleration vs speed) in lateral and longitudinal direction. The first steps have been implementing all what I did previously in Excel. So, after fixing the pillars of the tool, the most of the time was spent in adding small features that make using it more intuitive and improve its flexibility. The basics of this new tool remained the same, and that helped a lot at the beginning because it allowed me to focus more on coding and on finding the best way I could to reach the goal.Īnyway, as I will show in a few moments, I soon realized that Matlab offers a much bigger potential for building a similar tool, also in terms of user interface.
TIME MATLAB 2012 SIMULATOR
This is the topic of this article.Īs some (very few, most probably!) usual readers may know, I already built a Lap Time Simulator in Excel last year and went on refining and using it also this year.
This was surely a very interesting exercise: on one side it offered a chance for me to (re)establish a connection with Matlab itself (dealing with a topic I knew already) on the other side, there are some areas where Matlab is surely easier and faster than Excel, because a bit part of the necessary / engineering interesting math is already built in.Īnyway, I am still convinced that a suspension kinematics tool is probably not the best exercise to showcase what can be done in Matlab, so i soon moved to Lap Time Simulation. My last post here was about me switching to Matlab for the tools I built and use for my projects.īack then I wrote a bit about bringing into Matlab my suspension kinematics tool. Ok, now back to what I want to talk about today.
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