Musing #75: Analysing the Valencia Formula E debacle

 


Some may call it exciting and others farcical. For a fledging series, Formula E certainly attracted the wrong kind of attention with the slipshod finish yesterday resulting in only 9 drivers being classified at the end. While it is easy to call out the FIA or Da Costa for the extra lap, the reality, as always, is more complex. This analysis thus aims to clarify the events as they unfolded.

The first big question that I came across on the web was about the big change in energy reduction percentage during the various SC periods. While there was only a 3% reduction during the 3-minute safety car (SC) at the 20-minute mark, the final 5-minute SC resulted in a 12% reduction. Well, this is quite easy to explain keeping in mind the starting available capacity of 52 kWh. Essentially, the percentage value displayed on the screen is a relative value whereas the absolute reduction is happening in terms of kWh, both to the usable energy as well as available energy.

At 20:38 remaining, we can see that the available energy is 61%.

Moments later, it drops to 58% after the reduction.


The reduction itself is 3 kWh for that SC period and a total of 9 kWh for the race.


This latter part is the most important as it indicates the total available energy after the reduction. Back of the envelope calculations for this scenario is as follows. Note that these calculations are based on the whole number figures displayed in the TV graphics while the actual numbers with the correct precision would be slightly different.

Usable energy before reduction: 46 kWh (52 - 6)
Available energy before reduction: 61% of 46 kWh = ~28 kWh

Usable energy after reduction: 43 kWh (52 - 9)
Available energy after reduction: 58% of 43 kWh = ~25 kWh (28 - 3)

Now let us take a look at the final SC. The available energy is 18% prior to reduction.

It drops to 6% after reduction.

The total energy reduction is 19 kWh in total and 5 kWh for that SC period.

The calculations now are as follows:

Usable energy before reduction: 38 kWh (52 - 14)
Available energy before reduction: 18% of 38 kWh = ~7 kWh

Usable energy after reduction: 33 kWh (52 - 19)
Available energy after reduction: 6% of 33 kWh = ~2 kWh (7 - 5)

As you can see above, the percentage value can be quite confusing for the viewer as both the numerator and the denominator change by the same amount and thus the change in the actual percentage value will be more drastic for lower energy values than the higher ones.

That explains the TV graphics but then why were the teams caught so unawares towards the end? For, let us go to the period just as the final SC came out.


At this point, Da Costa has 22% of 38 kWh usable energy i.e. 8.4 kWh. The fastest lap as can be seen in the office notice was about 1m 40s. It thus indicates that at this point, there was enough time to cover 5 laps.

However, when the SC came out at 5:38 remaining, there was still a part of the lap remaining. Luckily, Da Costa floored the car at about the same place after the SC, so we can easily make out the time needed to reach the finish line from that part of the track.


As can be seen from the images above, it takes about 25 seconds implying that Da Costa would have crossed the line with 5:13 remaining if there was no SC. Considering the fastest lap of the race, 3 laps would have taken around 5 minutes. Thus, if Da Costa was to complete 3 more laps in 1:44 to 1:45 minutes, he would have needed to complete only 4 laps to finish the race with about 8 kWh remaining which is perfectly feasible.

The problem then is that the SC pace was not enough to scrub off a lap and thus the cars still had to complete 4 laps to finish the race, around 2 laps under the SC and a little more than 2 laps at race pace. While the race pace target was 2 kWh/lap, under the SC, assuming a lap time of 2m 30s, the reduction would have been 2.5 kWh/lap. This implies that the cars lost around a kWh of energy behind the safety car due to the time elapsed and at the same time utilised closed to 1.5 kWh of energy following the SC.

Thus, while in race conditions, Da Costa was expected to have 4.4 kWh of energy at the point where he started the final run with 2 laps to go, in reality he had about 2 kWh. The only feasible option was to limit the race to one lap after the SC which he was unable to do so. At the same time, Mercedes seems to have a 5-lap target in mind before the SC and thus were keeping more energy in hand compared to Da Costa who was hoping to limit the race to 4 more laps at the time the final SC came out.

While it was a shambolic end to the race with the FIA shifting blame to Da Costa for not controlling the pace, the FIA is not without blame. They had never made a provision for such a scenario and the fixed reduction of 1 kWh/min applied by the FIA is excessive when the usable energy is low.

One way of tackling such a scenario could have been to reduce the energy allocation for a race lap over a SC lap duration (i.e. ~2 kWh reduction over a 2:30m SC lap). This results in a reduction rate of 0.8 kWh/minute. If this seems too low a reduction, then the rule can be changed to apply this limit only for the final 10 minutes of the race.

The other option could have been to not deduct the energy consumed by the car behind the SC which seems to be about 0.3 kWh/minute (can be calculated from the fact that usable energy reduced from 22% to 18% behind the 5-minute SC with 38 kWh available energy). However, this would result in a reduction rate of 0.7 kWh/minute and thus even more benevolent that the previous approach which is in fact more practical as it takes in to account the energy consumption by the race car and SC for a specific track.

Will this situation be addressed? That is anybody's guess as Formula E certainly seems to be quite disorganised at present. However, the solution to the problem is available as highlighted above and all it needs is the FIA to act on it. Most probably though, I think the teams will adjust the software to account for the SC loss going forward and we might see a slow but secure finish if such a scenario arises in the future.

Musing #74: Designing Fossil Hybrid HR Watch Faces


  

Time pieces move on with time and the Fossil Hybrid HR happens to be the latest one occupying my wrist. I always have the urge to customize whatever I can get hold of and the McWatchFace was the first in this regard concerning a watch face.

Following that, I moved on to the Fitbit Versa 2 but I could never invest enough time to create a watch face for it.  I had the yearning for a more traditional watch, but ever since I started using fitness trackers, I can't completely wean myself off it. To that end, I got hold of the Fossil Hybrid HR a fortnight ago.

Having never had a Pebble in its heyday, this watch has been a revelation for me in terms of tinkering as it doesn't require much to design something new and share it with the world at large. With that, I present my first watch faces for the Hybrid HR. If you already possess this watch, then feel free to access these watch faces using the Fossil store and let me know if you have any ideas worth implementing.

6 B&W










Musing #73: Raspberry Pi 4B - SD Card vs SSD



Earlier this year, I bid finally bid adieu to my Raspberry Pi 2 in favour of the Raspberry Pi 4B. The RPi 4B certainly opens up new horizons with its additional power, though I don't suppose it is a desktop replacement as some marketing material would have you believe. I couldn't care less about that aspect as it is meant to be more of a hobbyist product, though I did switch over to MATE desktop environment from the kiddish-looking LXDE environment that the Raspberry Pi OS comes with by default.

What I was looking for most is the general increase in performance and with the BCM2836 SoC in the Pi 2 v1.1 not supporting USB boot, this was the first time I could boot off the USB. I immediately jumped on to the 64-bit beta back in May along with the EEPROM update that allowed booting off a USB drive.

I already had a Sandisk X110 M.2 SSD with me from an older tablet and a M.2 to USB enclosure. Unfortunately, I quickly realised that the enclosure was not up to the task as even loading the boot files failed repeatedly. It seems the controller on a cheap enclosure isn't really that good (who would have thought?), so it meant getting another one instead. I went with a ORICO one this time, not expecting it to be great but at least better than the one I had since it cost 3 times as much. Sure enough, it did the job.

So how fast is the SSD over the SD card? Unsurprisingly, it is quite significant. The lower power of the processor on the Pi gives a better idea of the difference made by SSD alone, though with it being limited to a shared 5 Gbps interface, the full extent wouldn't be evident if you plug in another USB 3 device or wastefully plug in a NVMe SSD instead of a NGFF one.

Long story short, unless you need your Pi to occupy as much less space as possible, it makes sense to boot off a SSD instead of a SD card. Also, if you have a good case, like the Argon One I picked up recently, it is possible to overclock it to the maximum 2.147 GHz without voiding the warranty and still keep the temperatures lower than the stock frequency without cooling. All this does tempt me to give the Pi a go as a daily driver, but for now there are many other creative uses for the device that take precedence. Until next time, Godspeed!

Musing #72: R.I.P. A50

Over the past few months, I had made multiple posts on the Samsung Galaxy A50, be it a short review, initial analysis of the super slow-mo or a guide about making the most of the mid-range hardware. Unfortunately, all average (good-ish?) things come to an end and in this case in ended with my A50 being lost. The driver of the vehicle in which the phone was left behind gave me some hope in picking up my call, but what followed left me with a little less faith in humanity.

However, life goes on and move on I have. At the same time, I have no emotional attachment to any material possession, so this post is not an eulogy on the A50 but rather a short post on what can be done to make the most of the situation where the phone is lost.

Samsung puts a fair amount of bloatware on its phones but one piece of software that is genuinely useful is "Find My Mobile". This feature is markedly better than what is offered by Google and there are several options for dealing with the lost device besides simply tracking it like erasing the device, ringing it, retrieving recent calls/messages and extending the battery life. Unfortunately, my trust in the driver led me to not immediately open the tracker which in turn ensured that the device was never again switched on with my account activated.


With the horse having bolted from the barn, there can be some solace found in rendering the device useless, well, as a phone at least. The Department of Telecommunications (DoT) in India launched the Central Equipment Identity Register (CEIR) earlier this month which is supposed to make the blocking of the lost phone as easy as snapping of fingers.

Unfortunately, as with any government initiative, things sound much better on paper and on websites than in reality. I went through the process of lodging a police complaint at the place where the phone was lost with the expectation of making the most of this lifeline afforded by the DoT in terms of being able to take some action on the lost device. As it turns out, while the website correctly verifies the IMEI using the dedicated tool, the form itself fails to submit with the error stating the absence of data for the IMEI. A really shoddy implementation by C-DOT backed by an equally appalling lack of response on social media. I would still give them the benefit of the doubt considering it has been launched as a pilot project, but hope they would be inclined to fix the website eventually.

Even every misfortune is worth the experience and I would say this is a lesson well learnt. A bit more practicality over trust in humanity might have saved the day. Hopefully, this post would equip you to better handle such a scenario in a far better manner than I did. See you until my next mobile adventure.

Musing #71: Samsung Galaxy A50 Super Slow-Mo and Night Mode


A little over 24 hours ago, Samsung introduced the Super Slow-Mo and Night modes to the Galaxy A50. While Samsung does an impressive job with camera improvements on flagship devices, I had my expectations pared down for the A50.

With all reviews down and dusted for the device at the time of its launch, it is unlikely that anyone other that someone who owns the device would test these features on a short notice. Hence, here I am with this post.

Super Slow-Mo Mode:

The A50 had a Slow Motion mode since launch. That mode recorded 720p video at 240 frames per second and played it back at the same rate. Hence, the super slow-mo mode was a bit of a mystery since there was no official mention of what it comprises of.

The super slow-mo mode in the S9 managed to do 960 FPS for 0.2 seconds. It seemed unlikely that Samsung would push a mid-range device that far even though it has quite a capable chipset. The marketing material mentioned the Exynos 9610 as being capable of recording Full HD at 480 FPS but was unlikely to happen.

The best way to find out what a new mode does is to test it out. Since there is nothing better than watching a (digital) stopwatch in slow motion, that's what I did. The process of recording itself gave no indication to what was actually happening since it would take over 2 secs for the camera to start saving after initiation of recording, with the saving process itself taking longer.

Normally checking the metadata would sort things out, but in this case the output was clasified as a 8m 33s, 30 FPS video; nothing abnormal about it but for the fact that it was supposed to be a super slow motion video. Thankfully, this is where the rather vapid stopwatch came to the rescue.


As can be seen in the video, the actual super slow motion part of the video lasts for about 0.4s, from 0.69s to 1.09s. The video itself  contains 250 frames, so to accommodate 0.4s of super slow motion implies that the recording rate was 480 FPS as it constitutes 192 frames (480 x 0.4). The remaining 58 frames are created courtesy of normal 30 FPS recording preceding and following the super slow-mo part of the recording.

It's great having super slow motion video but to have it at 720p when the chipset is capable of 1080p is a let down. But then, considering the struggles of the sensor to capture light even at 720p, it seems that a 1080p clip might end up being downright unusable. That Samsung has even bothered to add this mode to this device is a huge plus since few would have expected it.

Night Mode:

The clamour for Camera2 API for the A50 has been incessant, if for nothing else, than the ability to use Google's incredible Night Mode. However, it is unlikely that Samsung would ever accede to that demand. Instead, A50 owners get Samsung's take on the Night Mode which was always likely to be somewhat credible rather than incredible.

As always, in matters of camera, it is more apt to let the images do the talking. The rather compressed collage below gives an indication of how the various camera modes deal with extremely low light. It wouldn't take a detective to find out which one is which, so I'd rather take the easy way out of not labelling any of the images. However, for the purpose of verification and lack of astonishment, I have uploaded the original images with rather curt labels at this link.


Musing #70: Early days (of review)

It would be in good humour to pull a fast one on the 1st of April but keeping in line with what's in vogue with tech giants this season, I have refrained from doing the same; though you can always refer to my ode to this occasion from 3 years ago. This might however leave you wondering about the image accompanying this post.

Musing #69: Modern Monetary Theory


Heterodoxy can usher in amusement and stimulation in equal measure. In the context of economics, I have seen it pop up quite often at the mention of Modern Monetary Theory, to the extent that I have run out of fingers to count on. In the same breath, MMT (not this one) is equated with the license to print as much money as needed with it being a "creature of law". This makes nought sense to anyone having the faintest idea of economics and neither does the zero sum game between government spending and private saving.

Even if the theory has merits, it is often over-simplified by those pushing for its acceptance in the mainstream, which in turn makes it sound quite crazy. After quite some time, I have come across a source that does a simple and good job of discussing it. In general, I would recommend subscribing to the 'After Hours' podcast considering the fact that I ended up binge listening to it the first time I "tuned in".

Considering what happened in Zimbabwe, it will take a lot of effort to convince anyone that "unlimited printing of money by government" is a good idea, all things considered. At the same time, running fiscal deficits is a great idea, assuming there is a limit to it and that you are getting your money's worth. After all, debt makes the world go round. Running a deficit with a manageable debt-to-GDP ratio makes a lot of sense provided the government is getting a positive ROI in terms of social and economic benefits. What makes less sense is turning fiscal and monetary policies on their head without understanding their due impact.

There is no denying that the economic system is a belief and a social construct but there is no turning back the clock as well. Instead, the idea is to bring in meaningful change and MMT can contribute to that in parts, though not as a complete alternative. In the meantime, Calvinball anyone?

Musing #68: Making the most of Audible trial


Listening to a book doesn't quite have the same panache as reading one, but sometimes it is the only option. While I am an avid fan of podcasts on long commutes, sometimes audio books can fill the void quite well. However, in case of audio books, for me, it is unabridged or nothing, which depending on the author's preference for brevity can extend to numerous hours; a significant investment of time whichever way you look at it.