Data Analysis Fundamentals: Step 5: Analyse Driver Performance
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Step 5: Analyse Driver Performance
42.17
| 00:00 | - Step 5 is to go through and analyse the driver performance which is really going to be the real meat of this worked example. |
| 00:06 | Looking at how we can use the logged data to improve our performance. |
| 00:10 | So I've got the circuit tools software up on my laptop screen so let's jump over to that now and have a look through the UI and how it all works. |
| 00:16 | So for anyone using Windows, the layout of the software will be quite intuitive. |
| 00:22 | We've got really familiar tabs up here like file, home, session so let's go through each one of these. |
| 00:30 | This is where we can, in the file tab we can come through and load new data, we can modify the circuit which we'll come back and do in a second because I can see we've got too many splits sitting in there. |
| 00:40 | We've also got ways to access the quick start guide and the software guide as well as well as a place to check for updates which is a nice feature that it can do that automatically for us. |
| 00:50 | So in the home tab, we've got option to define which speed units we use, which distance units we'll use and which acceleration unit. |
| 00:58 | So for us we're using km/h metres and G force as our base units. |
| 01:04 | Here in the screen layout we've got options to flick through a whole lot of different pre defined layouts. |
| 01:12 | So we've got the default one up here which we're using, we can also go to a version which is looking at just the video. |
| 01:20 | So obviously we've got the 2 runs up here side by side, you can actually see here we've got, physically we've got 2 different drivers sitting in the car, you can see that they look quite different which is another advantage of having a rearward facing camera, it's another check of seeing who was in the car for which run. |
| 01:35 | We've got the ability to look at just the graph and the data on the side here. |
| 01:40 | We can, we've got another different view which is the combination view of the track on the left, a small data view, the video up here and some timing information. |
| 01:53 | I should say as well we've got the ability to resize any of these as we go if we want to. |
| 01:57 | If we want or need to to make any views larger or smaller. |
| 02:01 | We have an option to just look at the graph function. |
| 02:05 | So often if you want to look at something really detailed in the graph, you'll want to switch over to looking at the graph function, graph only function because that means, it just makes everything larger and easier to see all the differences. |
| 02:14 | So this is something when you're looking at the data in detail you will be coming over and using quite a lot. |
| 02:18 | If you need to look at the session data by itself which is obviously giving us the lap times and the sector times, I'll come back to some of this other stuff in a second when I go through what's involved there. |
| 02:28 | If we want to look just at the track view. |
| 02:30 | So obviously this is showing us for both pieces of data, one shown in red, one shown in blue, we can see the car as it moves throughout the circuit and we can also see the position of the cursor, it's showing us where each car is on track and you can see the start/finish line is indicated by this little green dot here and the sector lines which have been put in by default which we're going to go through and change in a second. |
| 02:52 | The sector lines are shown in with these blue dots here so we've got I think 5 or 6 sectors already defined there. |
| 02:58 | And the last one, view all is, as the name implies it just brings up every single display and again you do have the ability to resize things if you need to but it's just a way of bringing every single display up. |
| 03:11 | So let's have a bit more of a look through what we've got in the tabs here. |
| 03:16 | We've got some font controls, some language controls between English and German as well. |
| 03:20 | The session tab, we've got the ability to come through and edit the session information. |
| 03:24 | So in the same way that I showed you we had the dialogue box where we could modify this when we downloaded the data, we also have the ability to modify it after the fact which is nice if you need to, you realise there's a mistake in the details or you want to add more detail into it later, you can rename the current session, you can also export the video from the current session if you want to send it to maybe share on social media or share it with someone, you've got the ability to export it from there, you can also export the lap data as CSV as well if that's useful to you. |
| 03:55 | So if someone wants to import it into another data analysis program or they want to look at it in a spreadsheet or something like, they can do their own post processing, that's how you can do that there. |
| 04:04 | In the display mode you can look at the log file by the entire length of the entire log file or you can look at it by laps and by laps just means essentially we're zooming into each particular lap that we've got selected and we'll go through the lap selection of that in a second but often when you're doing an overlay of one lap to the other, obviously you'll be looking at one lap at a time so you generally want to zoom in and be looking at the by laps. |
| 04:26 | So you've got the option here to show the unfinished laps, or ignore the short laps here so it's just an ability to look, get rid of data that doesn't make any sense to look at. |
| 04:36 | If you only want to look at the fast flying laps then you've got the ability to filter those out there. |
| 04:40 | We've got options for the column options which are going to relate to which columns are shown in the data selection here, we'll go through this in a second but essentially you can see we've got the ability to turn off the delta column and the split columns if we want to. |
| 04:53 | We've also got options of how to visualise the post processing for those split times as well. |
| 04:59 | And we've got options to export and print what we see on the screen there if we want to share those with anyone. |
| 05:06 | For the graph controls we've got some basic controls around zooming in, zooming out and so if we wanted to zoom in on a particular section we can do that here and reset zoom will take us back to that fully zoomed lap. |
| 05:16 | On the graph you've got the ability also to zoom in by using the up and down keys on your, with your cursor to zoom in on a particular part and again we've got the same controls down here on the graph as we do up here in the task bar at the top. |
| 05:32 | We can pan left and pan right if we need to on the cursor. |
| 05:37 | We can zoom across both axes or zoom in X only which typically you'll be zooming in X only, that means in the horizontal axis you'll want to be zooming in one particular part on track that you have got the ability to zoom on both axes if you want to. |
| 05:49 | Now this control here about what that axis is set to is quite important so we've got the option of time, distance or position. |
| 05:56 | So in a lot of data analysis programs, you've usually got the option to switch between either time or distance. |
| 06:01 | The VBOX has got an option that you don't see in too many other data systems which is to do it by position. |
| 06:07 | So obviously we went through this in the course, we know if we're looking at the X axis on a time scale, that means that each data point is aligned by the time it was recorded in the log file. |
| 06:16 | Distance is what we're often using in most data systems because it aligns the data with the position on track or at least an estimate of the position on track which if we're doing overlays of drivers for performance reasons is often the one that we're looking at, we're looking at things by distance. |
| 06:35 | The extra option that the VBOX has is to do things by position index. |
| 06:38 | Now the difference between, and the advantage in doing it for the VBOX anyway in terms of doing it by position than by distance is to some extent is's correcting for differences in driving line. |
| 06:48 | So what I mean by that is the distance is something that is calculated from the GPS data as far as how far the car is moved around the track. |
| 06:56 | Obviously if one car takes a much wider line through one corner, you're going to potentially have, or you will have a car travelling much further and that can lead to skewing and offsets in our data like we've already been through in the course. |
| 07:06 | If you plot by position, in the background it's doing a calculation to try and align the car as best it can by the position, the longitudinal position on the track. |
| 07:17 | And in theory that's just giving you a slightly better potential alignment of the data. |
| 07:21 | Now obviously if you've got 2 cars going wildly different driving lines, while you can align by position, it's not going to be perfect. |
| 07:30 | But they do recommend, Racelogic do recommend using the position setting for the X axis when you're doing driver analysis so that's what I'm going to leave it on today. |
| 07:40 | Here we've got the option to change the smoothing which is similar to what we saw in the setting in the configuration options. |
| 07:47 | So what I'm just going to do here is try a couple of different options. |
| 07:50 | If you just watch on the acceleration values down here which is the longitudinal areas and the lateral is here, if I go through and change some of these. |
| 07:57 | If I change the smoothing factor to 5, you can see how much smoother each one of those gets. |
| 08:03 | Essentially it's just increasing the width of that moving average filter which has the effect of smoothing everything out. |
| 08:09 | Now smoothing is something you've got to use as a appropriate. |
| 08:12 | You don't obviously, over smoothing is going to dilute the signal down and reduce the peaks and troughs as well as getting rid of the high frequency noise. |
| 08:21 | But undersmoothing is going to make the signal excessively noisy and make it difficult to see exactly what's going on. |
| 08:28 | So I'm just going to leave it on the default value of 2, that's fine for me. |
| 08:30 | Again we've got the export and print functions here. |
| 08:33 | So in the print, sorry in the video section we've got options to play and pause, stop, move forward, move back, exactly like you'd expect. |
| 08:40 | You've also got the option to move through the lap with this position cursor which is a nice feature as well. |
| 08:46 | We've got some similar controls down here on the actual video window. |
| 08:50 | One of them in particular which I find is useful is to change the playback speed. |
| 08:54 | So I think we'll use this a little bit when we go through looking at the logged data in detail. |
| 08:59 | Often I end up replaying at half speed which I find useful for when you want to look at both pieces of video at the same time. |
| 09:07 | If they're running at 1:1 speed, if you're trying to flick your eyes between one and the other, I find running at full speed, it's a little bit more difficult to do but running it at half speed, it makes it a bit easier to pick up differences in the way the car's positioned on track and when the driver's turning in and just being able to compare them in real time. |
| 09:22 | That's obviously a preference thing. |
| 09:24 | With the track we've also got options in the track view perspective down here we've got options to zoom in, zoom out, just like you'd expect, pan around the track, centre on the vehicle or not. |
| 09:35 | So obviously if you centre on the vehicle it'll kind of move, as you move through the track you'll see here it'll keep the vehicle in the centre of the circuit or if you turn that option off on the track it'll keep the whole track shown the whole time so again that's just a bit of a preference thing here. |
| 09:51 | So we've got the option of the 2 different circuits we've had selected in here. |
| 09:55 | So we've just got the Highlands Motorsport Park here selected by default which is the correct circuit for us anyway. |
| 10:03 | In the data section we've got the ability to, this is the data tab down here, we've got the ability to, sorry this is the data section in the bottom left here, we've got the ability to show the current value in these columns, the minimums, the maximums, the range, the delta which is, the delta's just the difference from one log file to the other, rather than showing the absolute value, the actual values at that position, it'll show the value in the overlaid data vs the reference and you'll see how we select that stuff in a second but in some cases you want to look at the delta, sometimes you want to look at the absolute. |
| 10:36 | And you can also look at averages as well so you've also got some similar controls down here that you can use and it shows our text value here, what setting we've got, so whether we've got current, minimum or maximum just to make it a little bit easier for the user there. |
| 10:49 | So that's it for the main bar at the top. |
| 10:52 | The first thing I want to go through before we get into the analysis is reduce the number of sectors. |
| 10:56 | So like we talked about in the course, having too many sectors and certainly having sectors that start and finish within braking zones, within corners is something we generally want to avoid. |
| 11:04 | It means things end up being a lot more variable, we usually want to out our sectors along straights, in places where there's no cornering and there's no braking or accelerating, or sorry no accelerating out of the corner happening anyway. |
| 11:17 | So what I'm going to do is go through and modify the definition of this track. |
| 11:20 | So if I come up to the file here I've got the start/finish line wizard. |
| 11:23 | Here we've got some controls set out for us. |
| 11:28 | We've got, it tells us we want to use the left mouse click to set the start/finish line and the right muse button to set the splits. |
| 11:37 | Shift left is to change the finish position. |
| 11:40 | By default the start/finish line I'm fine with, I don't need to change that, it's only the sectors I want to change so it's saying here use shift to control and right to remove the selected split. |
| 11:52 | So what I'm going to do to start with is go through and remove the selected split. |
| 11:54 | We can see the raw logged data from this data file, we can also see this one off to the side here which is actually the car coming in and out of the pit lane which is picked up on the GPS data there. |
| 12:04 | So what I'm going to do is I'm going to hold shift and control and I'm going to go over these sectors I want to get rid of, right click, that removes it. |
| 12:11 | Right click again, again and again. |
| 12:17 | Now I'm going to make this 3 sectors which is usually enough on the average length racetrack to give us usable sector data. |
| 12:24 | So I know that this section of track here is where I want to put one sector. |
| 12:28 | I know that if I go in this section here, the car is well before the braking point so I'm going to come back here and right click add a sector there and the other place I want to put a sector definition is in this straight section down here, well before the braking zone. |
| 12:40 | So I'm going to put one there as well. |
| 12:42 | So now I'm happy with that, I can continue onto the analysis and you'll see our sector definition changes in our track map down here and it also changes in our splits column. |
| 12:51 | So let's go through what we've got out here in the actual data section. |
| 12:54 | So you can see here that we can tab through both of the different log files that I opened. |
| 12:59 | So we've got our slower lap which is our 1:48.5 from our amateur shown here in this log file and we've got our faster lap from our pro which is the 1:47.3 which is shown in this tab. |
| 13:08 | Now you can see we've got, this is pretty self explanatory but essentially whatever overlays we want to show, we've got the option to select here so by default, the software will automatically select the fastest laps for us in each log file which is often the thing you're looking at, not always, sometimes you want to go through and do things a bit differently but we, by default it's showing us the fastest lap in each log file if I want to go through and select another one, if I wanted to go through and look at this 47.7 here, you can see it adds a 3rd overlay, it changes, automatically brings up the linked display of the video and you can actually see it's added in another line in here, into the data and, sorry in both the logged data and into this data view here. |
| 13:51 | Now you have got the option to change the overlay colour. |
| 13:54 | Green is typically a really hard colour to see so let's say if you wanted to make it, maybe let's go for a darker green here, make it a little bit easier to show up here on the plot. |
| 14:03 | But just for a start I'm not going to show this, I'm just going to look at the two fastest laps to do the overlay difference. |
| 14:09 | So you can see obviously we've got which laps we want to show, we've got the definitions, the colour, if we want to, how we want to highlight them on the analysis software, which lap number it was within the stint. |
| 14:20 | What the lap time was, along with each one of those laps. |
| 14:24 | What the delta was to the fastest, the delta again just means difference. |
| 14:28 | And we've got the option here for the datum so we can make the datum whatever we want. |
| 14:32 | By default the datum will be the fastest lap that you've got loaded but you've got the option to make the datum, as in what the reference lap is to whatever you want. |
| 14:38 | So in this case it's set correctly, we've got the datum is set to the professional driver which is what we want to use. |
| 14:44 | If we wanted to change the datum to the amateur driver was can come over here and set the datum and essentially just inverts everything and makes everything relative to that, amateur driver relative to the pro. |
| 14:53 | But I'm going to come back here and just leave that set on the pro driver. |
| 14:56 | And the last column here is showing us our sector times, so it's automatically updated and shown us our new sector times relative to the new sectors we have defined there. |
| 15:11 | So here we've got everything shown in delta mode relative to the, this is showing us relative to our fastest lap so we've got the absolute times shown down here for each sector and then we've got the delta, the difference to each one to our reference lap shown in both and that's shown for both of them here. |
| 15:29 | So in this particular run we can actually see the amateur in the first sector is actually, essentially equalling the time through the first sector marginally slower but we can see it's really sector 2 and sector 3 where all of these differences are starting to stack up here as well for us. |
| 15:46 | So that is it for the lap selection. |
| 15:49 | Obviously it's pretty self explanatory, the video display is shown up here for us. |
| 15:54 | The nice thing about the software is if we come through and click the cursor in different parts of the lap, you can see the video is updating automatically for us and that's really a fundamental part of the VBOX system and it's automatically handling that sync for us. |
| 16:08 | As you'll see, as best it can anyway, it'll be syncing by position on the racetrack which is really important because we want to be comparing like with like. |
| 16:17 | We want to be comparing the same position on track. |
| 16:20 | You will find there's lots of other data analysis systems out there, lots of them do automatic syncing. |
| 16:25 | If you're using something like a Go Pro, with whatever logging system you're using you'll often have to do it manually which does add quite a lot of post processing time to what you're doing so absolutely using a system like this when it does the syncing for you automatically can be a big advantage. |
| 16:39 | In the bottom left here we've got the data, the raw data shown for us at the position where the cursor's shown. |
| 16:45 | Because I've got it, let's set it on the current view here, that means wherever I put this cursor throughout the lap, it'll show us the value for each of the log files. |
| 16:55 | So by default here I've got speed, lat, long acceleration and also the delta T which is our time variance channel. |
| 17:03 | So we've also got, we can also come through and select anything else we've got here so if we wanted to look at the longitude position throughout a lap or we wanted to look at the distance channel throughout the lap, you can see both of those plotted on there as well. |
| 17:18 | If you're using the default, the default logging parameters and not having any external data going into this system, just like we do here, the most useful pieces of data that you're going to have are the speed trace, the lat and the longitudinal G force and the delta time and that's what we're going to be using for this analysis here. |
| 17:34 | So if you want to look at a particular point on track you can come through and use the cursor and that'll give you the readout for both of the different log files that we've got here. |
| 17:42 | So the convention we're using through all this analysis is we've got our blue colour selected up here for our reference time for our pro and the red is going to be for our amateur's data and that convention is shown the same way throughout all of the software so for the data plotted, for the table here and also obviously the highlight for the data that we've got shown at the top here. |
| 18:01 | So now that you've got a bit of an understanding of how the user interface works, we'll go through and actually get into some of the analysis. |
| 18:07 | And find the places we're actually losing time on track. |
| 18:10 | To start here I'm just going to go through using the time delta or the time variance channel and look for our biggest losses that we've got occurring throughout out lap. |
| 18:18 | So I'm just going to come across here and just use the larger data view for a start. |
| 18:23 | I don't need the video for this so I'm just going to look at what our biggest losses are. |
| 18:26 | So anything, remember our pro is in blue which is going to be shown as a 0 in the delta time because that's our reference and the amateur is in red so anything below the 0 line here is actually going to indicate that you've got a gain or that's something that's going to be better than the reference and anything that's above it is slower than the reference. |
| 18:47 | So interestingly enough what we've actually got going on here is at the start of the lap, the amateur is actually making a gain on the pro leading into the first turn. |
| 18:56 | So coming up here and looking at the speed trace we can see why. |
| 19:00 | They've got a lot more drive coming out of the previous corner at the start of the lap and that's why they're making all of this time. |
| 19:05 | Now whether that's down to a car difference which it shouldn't be, or whether that was down to maybe the pro having to pass a car or deal with another car on track coming out of the previous corner or just getting a bad run of that previous corner, that shows us straight away that we've got the amateur actually doing a better job at that point but what we do see is there's a big loss here. |
| 19:24 | So while the amateur is making a gain in this section, straight away they're making a big loss down here at this point here which is what we want to concentrate on. |
| 19:32 | So this, anywhere where you've got that steep gradient, that's a point you want to concentrate on because a steep gradient indicates a big time loss or a big change in the time delta. |
| 19:41 | So I would say that this position down here is one of our points that we want to focus on. |
| 19:45 | This position here, you can see the time variance has come back to roughly 0 so all of the gain here, the amateur had made at this point, they've lost in that first turn and coming into this part of the track here there's essentially no difference between them but then there's a again a big steep loss, big time variance difference between them. |
| 20:06 | So I would say this is another place we want to look at. |
| 20:09 | If we want to look at the time difference, so if we out the cursor here, time delta here, we've got, essentially they're both on 0 but if we want to put the time delta, we look at, once we get to the mid corner how much time has been lost by the time we get to the mid corner, we can see it's 0.39 so roughly 4/10 of a second lost in that just one braking zone which is a pretty big loss all by itself. |
| 20:29 | And then the last loss I want to look at here is this section here where we've got this big jump in the time variance again. |
| 20:36 | So we look at the difference between them, we've got 4/10ths difference at that point and by the time they get through the corner, let's say we've got that point there, roughly 8/10ths so again, another 4/10ths that's been lost in that section so these are the 3 points we're going to concentrate on. |
| 20:52 | This point here, this point here and we're going to concentrate on this point here as well that we're going to now dig into the actual log data and figure out what's going on. |
| 21:00 | So we'll start by looking at the actual logged data and then we'll come back and use the video to give us a little bit more context about what's going on with the car in a little bit. |
| 21:06 | So for a start off let's look at this section of the track like we said. |
| 21:11 | Now we can just hold and drag and that'll allow us to zoom in on that particular section. |
| 21:15 | Now while we do have this difference in the speed trace, I'm more interested in this big loss that happens here so we can see that that's happening around about this section here and we can see that that's happening in the longitudinal G force, that's telling us straight away that the amateur driver is braking a lot earlier than the pro. |
| 21:33 | So one of the ways we can do that, we can check that, I'm just going to drag this up so I can see the distance channel on here. |
| 21:39 | You'll notice I've got the X axis set on here by position so we're not going to read the distance directly off the X axis down the bottom, we're going to read the distance off this channel here down in the details box where it gives us the raw values of the logged data. |
| 21:55 | So I've got the cursor about the point where the amateur is rolling off the accelerator and onto the brake. |
| 21:59 | Incidentally you can actually see this situation here. |
| 22:03 | So as the accelerator gets rolled off you end up with this sort of slow change in longitudinal acceleration so we're going from a positive longitudinal acceleration at this point, rolling off gradually through 0 and then coming into a steep negative. |
| 22:16 | This gradual roll here, that's what you see when the driver is getting off the accelerator. |
| 22:22 | When they get off the accelerator, obviously you've got no more forward acceleration, you've got the aerodynamic drag taking over and you'll see that slow change in longitudinal acceleration. |
| 22:29 | It's not until you actually get on the brake pedal that you end up with this steep line that we see here in the longitudinal acceleration. |
| 22:34 | So if we place the cursor at the point where the amateur starts braking, we've got 204 metres shown here on the distance and we come across to where the approximate same place that the pro is doing it, we've got 248. |
| 22:47 | So that's 248 vs let's say 205, so let's say ballpark 40 metres difference which is an enormous difference in the braking point there. |
| 22:57 | So straight away we can see where some of this big difference in performance is coming from, it's coming from the amateur braking roughly 40 metres earlier than the pro so that's explaining part of our difference. |
| 23:11 | The other thing is if we look at the slope of the longitudinal line here, it's much much steeper than what's happening for the pro. |
| 23:19 | So one of the reasons for this, if we come and look at the speed channel here, what's that current speed, at the slowest point after we've got through this section of the track which we'll see on the video is actually a little bit of a bus stop chicane before it heads into a long corner. |
| 23:32 | We're still doing 140 km/h at this point at the slowest point after we've got through that section so what you'll often see here is a pro driver will often, well when the car's being driven well, you won't necessarily see these big really aggressive brake inputs. |
| 23:46 | This is a situation where you probably want to get onto the brake a little bit more gradually, you don't want to be too aggressive to the car. |
| 23:52 | In a place where you're running into a section of track where you've got a flip flop like we do here, this is a left right through a bus stop. |
| 23:58 | Because you don't want to transfer a whole lot of, you don't want to upset the car too much, you don't want to transfer the load to the front axle too aggressively so this is a situation which is what we see in this case where the pro is using slightly less aggressive braking in order to get the car settled so when he heads into this flip flop he doesn't want to be unsettling the car too much. |
| 24:17 | So that's again the difference here, the driver, the amateur driver is using probably too much brake application, they're probably using too much brake force, too aggressively here so the amateur driver, the difference here is the amateur driver is braking much later but they're also being a little bit more gradual in how they apply the brakes as well. |
| 24:33 | So that's really the main difference here, now if we go back to the, let's have a look at the view all section so we can see a little bit more context. |
| 24:44 | So we can see down the track map here in the bottom right, this is the sort of bus stop chicane that I'm talking about that we've got happening. |
| 24:50 | This is the section of track that all of the stuff is happening. |
| 24:53 | Let's actually go to a larger view of the video as well just to give us a little bit more perspective about what's happening in the video. |
| 25:05 | Now what I'm going to do here is I might go a little bit smaller just so we can see the data a little bit better. |
| 25:13 | So if I go through and play this, I'm going to play it at 1 times speed at real time speed to start with, you can see both drivers coming up and getting on the brakes. |
| 25:24 | Turning into this section, curb, curb, another curb and then getting into this really long sweeping corner which you can see up on the track map here, the car is going through this chicane and then going through this long sweeping corner so that's the series of track that we're looking at in this section. |
| 25:40 | Now one of the things that's really useful about the video is we want to look at the driving lines where the driver is positioning the car and also when they're doing their turn in which is something that the video is almost indispensable for, it's giving us a lot of context about how the car's being driven, how it's placed on the racetrack and how it's being turned in. |
| 25:59 | So let's have a look at, see what we can see, if we just look at, just at exclusively at the video view here, let's have a look at a half speed. |
| 26:12 | Now I'm just going to zoom back in. |
| 26:18 | To this section, sorry I'm just going to come back here. |
| 26:25 | What I want you to pay attention to, we're going to look at the way the pro is positioning the car on the left hand side vs the amateur. |
| 26:31 | So for a start, I'm going to run this at half speed, we've got our braking marker somewhere up here. |
| 26:36 | We're just going to understand how the driver, how the pro driver is positioning the car, take note of where they're braking and when the car turns in, when you see it change in direction here so I'm just going to play this here, let me go back a little bit further because that wasn't quite enough for you to see that. |
| 26:51 | So he's exiting the first turn here. |
| 26:53 | Now just pay attention to how the car orientates itself here, so he's right on the outside of the track and he very quickly turns it in at that post there, we see we've got that orange post, that's kind of the reference he's using, just coming up here, and turn, right as he gets up to that post, you can see him making quite an aggressive turn in manoeuvre and that's part of what I was talking about is why he is using a less aggressive brake application. |
| 27:20 | Because he's using such an aggressive steering input there, that's why he's using a less aggressive brake application later on because he's trying not to unsettle the car as much. |
| 27:29 | Now let's look at the same position, let's look at the way that the amateur is driving the car. |
| 27:32 | Same position at half speed so we're looking on the right hand side here, towards the outside of the track, similar position. |
| 27:40 | And turning in much much much much later. |
| 27:42 | You can see, we knew the pro driver was turning in just as he was getting to that orange marker, let's look at where the amateur, let's review that again. |
| 27:50 | You'll see the orange marker coming up here on the left hand side, we are passing it now and he's only starting to turn in now. |
| 27:57 | So it's a really different approach to that corner, the amateur driver is driving in much straighter, so they're doing their braking in a much straighter line and they're doing their cornering much later into the corner. |
| 28:08 | Now one of the reasons that's probably not ideal in a situation like this in the bus stop is it means that because you're doing more cornering later into the corner, that means you've got more lateral combined load on the car, that means you've got to be careful with your brake application, it means the car's going to be more susceptible to be getting upset. |
| 28:27 | So what the pro is doing is that they're driving to their marker, they're getting all the turning done really early and then they're driving straight through that chicane. |
| 28:34 | That means that they're driving much straighter as they get to the loaded part of the chicane and they've got much more ability to modulate the brake and the accelerator through that section without being worried about loading up the car laterally and having, losing control of the car by overloading the tyres. |
| 28:52 | So that's really the biggest loss that's happening at that first part of the track, let's move onto the further parts of the track and analyse the next parts, let's see what we see there. |
| 29:02 | Moving onto the rest of the lap, let's have a look at what we've got. |
| 29:05 | So this is our second part that we want to analyse, we've got this big loss coming into this section. |
| 29:12 | So let's have a look on the track map, just gives a little context about what's happening with that. |
| 29:15 | This section up here, so we just, we can see where the cursor is on track and it's just this S section so we've got a left, a right and a left which are all a relatively similar radius which is a really tricky section of the track to get right. |
| 29:28 | So we want to understand what's happening with this big time loss. |
| 29:32 | I think we can probably anticipate what's going on pretty clearly by looking at the speed trace you can see a big loss happening, starting here and we can see going with it a big difference in the speed trace up here which is absolutely what we expect to see between a pro and an amateur often is just the ability to brake the car close to the limit. |
| 29:53 | So let's go back and dig into our data view again, have a bit of a dig into exactly what's going on here. |
| 30:03 | So let's zoom in. |
| 30:06 | Again you can see really clearly in the longitudinal acceleration we've got the pro, so the amateur in red, braking quite a lot earlier than the pro. |
| 30:16 | So let's have a look here, what the distance channel says, the distance channel down here, we've got 1090 vs 1106 so that's roughly 15 metres difference which in a section like this, of track, it's still a pretty significant difference in braking point. |
| 30:33 | For a professional or at a really high level you'd really expect the braking markers to be within, depending on the speed obviously, depending, between 2-3 metres within each other repeatability, 15 metres is definitely too early, it's definitely quite a big difference. |
| 30:49 | Again this is a situation where we see if we look at the aggression, the slope of the longitudinal axis, sorry of this longitudinal acceleration is relatively similar. |
| 30:58 | So the rate of brake application and the intensity on the build phase anyway is pretty similar between the two but what we do see again is the amateur driver going with a significant amount more negative longitudinal acceleration, that means that they're using significant amount more brake pressure. |
| 31:17 | So again they're over slowing the car through this section. |
| 31:20 | So we do see quite a lot steeper gradient through here on the brake trace, particularly once we get to this larger peak pressure. |
| 31:30 | So that's really where the start of this loss is happening through over slowing the car and then obviously the whole way into corner entry through this braking phase, they're consistently losing time the whole way through. |
| 31:42 | Anywhere where you've got this delta, this difference in the speed trace, you're going to be losing time the whole way through that section and that's really what we see is the whole way from the corner entry to the apex, or to the apex here, roughly here, that's where we see the biggest time loss taking place. |
| 32:00 | Now once we get to the apex and through this section, there isn't actually much difference, I mean there's a bit of give and take in the time delta, he's gaining a little bit back through here where he's getting into a little bit more peak speed at the corner but then he's losing it back here on exit so really the biggest gain that we want to concentrate on, we do want to concentrate on those big differences to start with and as time goes on, it'll allow you to dig into more of the finer details, but we do want to concentrate on these big chunks of time first that we get right. |
| 32:28 | So there's something else I want to point out here in the lateral acceleration which is the way the car's being turned into the corner. |
| 32:35 | So you've sort of got this initial, obviously got our 0 line here on the lateral. |
| 32:39 | And as the car's being turned into the corner, you've got this big second steering input that's happening by the pro just as they are about to start putting the brakes on and you've got quite a different application of steering that's happening with the amateur here so where they're actually turning in quite a lot and they're actually backing out of it a little bit once they get, I think they probably come in here, put a little bit too much lock, realise that they're going to be turning too much and straighten the wheel back out again, that's what we're seeing there. |
| 33:07 | Let's have a look at the video, let's see if we learn anything by looking at the video as well. |
| 33:13 | So playing this at half speed, so look at where the car's positioned. |
| 33:22 | Note how he's running through that section there. |
| 33:25 | Now let's look at the same thing, see if we see anything markedly different from the amateur, let's see if we pick anything up on the right hand side here. |
| 33:36 | Definitely a difference in the way that corner entry is approached, that initial turn in phase so let's go back and look at the pro again, see what we can pick up. |
| 33:43 | My impression is it's similar in style to what was happening at the first chicane where the pro is certainly making their way gradually out to the outside of the track but they're more sort of pointing the car at that braking marker before making quite a defined effort to get most of the turn going quite quickly and pointing the car back in so it's more driving straight at the braking marker, turning, braking and getting into the corner whereas a much more flowing style that we've got coming from the amateur here so let's watch what's happening with the pro again. |
| 34:16 | Really driving hard and from my perspective driving hard at this point, this reference point on track. |
| 34:23 | Whereas the... |
| 34:26 | ...let's pause that and bring it back. |
| 34:29 | The amateur is much more flowing in the way they're sort of, much bigger wider arc here getting the car turned, getting the turning done a little bit earlier as well. |
| 34:38 | Relatively similar over the curbs. |
| 34:42 | This is a good example of while there's not as much time loss going on in this section, what we can see is the amount of curb difference that's being taken through here. |
| 34:51 | So we can see the way the car is positioned for the professional driver, he's, it really looks like the entire car, may be easily even over the curb here so he's really mowing over much much more of that curb, he's going to end up being really close to this tyre bundle here where we see the amateur's leaving quite a lot more time on the table as far as eating up that curb. |
| 35:11 | In a section of track like this, it's track dependent but in this particular section of track, taking more curb there would be advantageous, getting over more of the curb. |
| 35:20 | So whether he's doing that intentionally or whether that's happening because he feels that he can't get the car over there quickly enough without unsettling it, that's something that has to be determined once you debrief them and can go through the data with them and actually understand why they're doing that but that's again another feature that I'd be pointing out, just giving them another reference, getting to get all over that curb just like the pro is doing there. |
| 35:44 | So let's go back and look at the video and the data together. |
| 35:50 | I'm just going to reduce the size of the video just to give me a little bit more perspective on the data. |
| 35:54 | So that's what we're seeing here in a, with the amateur with this steering input, this longer, slower, more gradual steering input which is what we're seeing reflected in the lateral G force here is also what we're seeing reflected in the video. |
| 36:08 | Whereas the pro is more, he's turning back towards the braking marker here, he's driving it much straighter at the corner which is what we see the lateral acceleration is sitting on the 0 line before being much more abrupt with their steering input as they, just before he gets on the brakes. |
| 36:25 | So you can see, and that's really what we see reflected in the video as well but you can see much more abrupt steering input followed by once he's got to peak steering input there, that's when he's really getting on the brakes really hard, turning down and then braking. |
| 36:38 | Happening much more abruptly in a much shorter space of time than what the amateur's doing. |
| 36:43 | OK so that's that section of the track we've looked at. |
| 36:46 | Let's look at the last one, so let's zoom back out here and look at our last section. |
| 36:51 | So the last section of track is another chicane section which, let's go back to, I'll just explain exactly where we're looking at here. |
| 37:00 | If we go back to the track view, it's this section of track here, essentially we've got this crossover in the track, so in this part of the track here we've actually got a bridge where the track goes over another part of the track. |
| 37:10 | So you're coming around this long straight here then you're braking for this chicane which is intended to slow you down as you head across this bridge here. |
| 37:18 | So this is the section we're going to analyse next. |
| 37:22 | So if we come across to the graph view, let's have another dig into what's going on here, and again almost predictably we can see a similar trend to what's been happening everywhere else in the lap which is that the braking point is much earlier and also that the braking intensity is much higher from the amateur. |
| 37:44 | So again let's just put our cursor on the approximate point where they're lifting off the gas and starting their braking, we've got 2873, sorry 2673 vs let's get an approximate point, roughly 27, so 27 vs 267 so roughly 30 metres so that's a really, again a really significant difference. |
| 38:07 | Now this is understandable, in some ways you've got a, this is really high speed section of track that's going into a relatively technical section through this chicane, this flip flop we've got to head up before you head up over the bridge. |
| 38:20 | This is going to be a relatively intimidating part of the track for a driver to deal with. |
| 38:24 | So it's not a big surprise we've got them braking a lot earlier here and also you see how much more, the huge difference in their braking intensity here with the difference in longitudinal acceleration and you see that reflected really clearly up here in the speed trace, look how much more speed's being just absolutely pulled out of the car at this point. |
| 38:41 | A massive difference in speed, if we look at this difference in speed as they're starting to release from the brake pedal, we've got 160 vs 140 so 20 km/h difference between them, it's massive. |
| 38:52 | And that is really what all of this big difference in speed trace is coming from. |
| 38:55 | Sorry in the time delta, so once they start losing this time here, it really compounds the whole way through, once they've lost this time back here, they never really regain it so from the point, let's look at the time delta that we've got here, so just over a 10th to just over, almost 5/10ths so let's call it 4/10ths just lost in that one section of track which is a really big chunk of time, particularly when you've got roughly 1.2 seconds difference between the lap times. |
| 39:23 | So again there's a big difference in the, how the lateral G is being applied. |
| 39:30 | In this case it's quite interesting, we've got the reverse of the trend, what we saw earlier, we've got the blue driver which is our pro driver on the faster lap doing more turning earlier and we've got the amateur driving in much straighter, so essentially they're doing all of their braking with the steering wheel much straighter before, as they start to release the brakes, so after they get to peak brake pressure here, they've started to bleed and then they're doing all of their steering. |
| 39:56 | So they're using much less combined load which is again another feature that you'll see if you were to do a traction circle or a GG plot, you would see in this section of track at least, the driver using much less combined load through that section of the track. |
| 40:09 | It's definitely quite technical, it's understandable that there's a big difference here between the pro and the amateur. |
| 40:15 | So let's go back and have a look at how the car positioning looks through this section of the track, let's see if we see anything much different in this so let's go back to the full graph mode. |
| 40:29 | And let's just watch this at half speed so let's watch the pro to start with. |
| 40:33 | Really hugging that outside line, really straight, really straight down that outside line, they're giving themselves as much room as possible. |
| 40:41 | You can see they've got a reference there that they're using, that they're picking up which is this curb, we've got an alternate part of the track here that joins at this point and you can quite clearly see that they're using that as a braking reference. |
| 40:54 | And you can see how they're following through there, probably didn't take as much curb as they wanted to, probably ideally would have taken a little bit more curb through there just to open up the corner a little bit more. |
| 41:03 | So we're looking at this section here, we can see the driver's doing a last little jaunt away from that section so they don't run off the edge of the track there, let's compare that to what the amateur's doing so let's just rewind here a little bit, let's look at the whole section following the outside line, braking a bit earlier. |
| 41:19 | Turning in, plenty of curb, that's good, but one thing you do see is that they end up being probably turning a bit too much in this first section because they end up pointing a lot more to the left, a lot more to the inside, a lot more to the left from their perspective. |
| 41:37 | You can see the difference in the positioning if we just scroll back a little bit further. |
| 41:40 | You just look at the different attitudes of the car, the pro is, just make that a little bit clearer by, if you watch the pro on the left, they're heading towards the grass and making one last little jaunt across. |
| 41:53 | Because the amateur is ending up to the left side of the track a little bit earlier, rather than running across and absolutely maximising the use of all of that outside curb, that'll be costing them a little bit of time through there as well. |
| 42:03 | So that's a relatively in depth run through of the points of greatest loss between those 2 laps that we're going to analyse. |
| 42:09 | Now we can move onto the last step where we apply it to the driver and find the gains on track. |
