Displaying on a larger screen

I have been contemplating the screen size for post analysis. There appear to be two options a 10" tablet and an android emulator for the PC. I have discovered an app called BlueStacks (http://www.bluestacks.com/)  that appears to solve most problems except printing. It does have a Print Screen facility. I have not tried running RaceChrono yet on an Android tablet.

The following shot was taken from my Zoostorm W7 PC and Samsung display.

Track experiments with RaceChrono

Kames - test day 31/08/14

Normal

Kames is a fabulous track located in East Ayrshire with some very technical skills needed to master it's curves. The normal direction is clockwise. The standard run is 2 1/2 laps and therefore you have to interpret the RaceChrono - tablular results to obtain a lap time that compares with a completion timing result.

* Split 1    Start - Hairpin 1
* Split 2    Hairpin 1 - Finish
* Split 3    Finish - Hairpin 2
* Split 4    Hairpin 2 - Start
A competition lap consists of  two complete laps + Split 2. In  the example below 34.24 + 33.45 + 12.8 = 80.49s


Normal Times

 You can relive the event by scrolling thru the data visually


Normal Track

 Reverse

This is exactly the same GPS data that I had previously blogged but I have rearranged the traps so I can more readily obtain a more comparable track time. This is done by treating it as 3 laps and subtracting off the excess data.

* Split 1      Start - Hairpin 1
* Split 2      Hairpin 1 - Finish Bend
* Split 3      Finish bend -  Paddock bend
* Split 4      Paddock bend - Start

 

This version of the track is 2 1/2 circuits also similarly interpreting the data 35.09 + 33.48 + 18.32 = 86.88s. Obviously I need to work on the normal direction.

Golspie - Kylestrome 09/07/14

 Golspie is a Kart track similar to Kames and again you need to arrange the split times so you can calculate a comparable event time.

* Split 1     Start - speed trap
* Split 2     speed trap - hairpin 1
* Split 3     hairpin 1 - Third corner
* Split 4     Third corner - Finish trap
* Split 5     Finish trap - Start


The direction this fine day was clockwise or Kilestrome format. Again to get a comparable time 49.76 + 39.14 = 88.90s

Forrestburn - track day 22/08/14

Forrestburn is my local track and is about 1/2 an hour away by van and trailer. I did an all day session on Sunday 22nd. For some reason after lunch I started a new session rather than continuing with the morning one so I have two sets of results.

* Split 1  Start - Hill Top
* Split 2 Hill Top - Hairpin 1
* Split 3 Hairpin 1 - Hairpin 2
* Split 4 Hairpin 2 - Finish

The results are just what appears on the tin and in this case the best lap was 53.5s second last lap of the day.

Conclusions

It is a pity the app is not more suited to sprint tracks where there are partial laps involved but with careful position of the split lines and some mental arithmetic a comparable result can be calculated. The convenience of a record of your results in your smart phone is a considerable advantage (I hope).

New Lap Timer

Frustrated with the lack of reliability and predictability of the Sumomoto GPS integrated lap timer I decided to invest in a Qstrarz Extreme 10Hz GPS and an application on my smart phone called RaceChrono for collecting the data. The perceived advantages are that these products are more predictable, reliable and less time consuming to illustrate the results.

Predictable: In that if I kick off the RaceChrono (on my smart phone) and it looses the whole sessions data then the GPS memory will still hold a record of the tracks (42hours worth).

Reliable: The GPS has a more sophisticated receiver that is less likely to loose lock (Adopt MTK II latest chipset with high sensitivity - 65dBm and  66-Channel tracking).

Less Time consuming: The results can be directly imported into RaceRender the visualisation software.

The disadvantages are 1) The GPS has to be mounted away from my roll-over bar for best reception as it has no remote aerial 2) The lap times have to be computed for the likes of Kames.

The first problem to solve was the waterproofing and location of the device away from the cage for best reception. I did this by mounting it in a dummy camera box (see pictures).

The second issue is to program RaceChrono to adopt a track, that is known to me and where I can do some testing on. I decided to use the Kames test day on 31st Aug 2014.

The problem with sprints is the track is not a simple circuit. It starts with a run up area to the first hairpin and does two and a half loops then has a run down area towards the paddock turnoff. I decided to nominate several split points so I could maximise the information from the trail runs.

* Start point
* First hairpin
* Finish bend
* Paddock bend
* Paddock exit

The first lap progresses from the start point to the first hairpin, then to the Finish bend, down to the paddock bend, then back towards the first hairpin, then back towards the Finish bend.

Then it repeats on a second loop missing out the Start point, then a third loop finishing at the Finish bend.

Track input

The problem with all this is that RaceChrono knows nothing about the Kames unique 2 1/2 laps that constitute the competitive track.

GPS disguised as a camera

GPS exposed

 

Timing analysis by data points and position on track

confusing split times.

 Competition type result analysis.

The above split times are of minimal use as the smart phone app does not know the shape of the real track with it's 2 -1/2 laps. However using the Timing analysis you can reconstruct a real lap time.

A lot of discussion in the paddock took place as to what time my car was actually doing in a conventional type lap situation. I have taken that to mean Finish bend to Finish Bend. From the above data extracted from the Timing analysis screen (resolved to 0.1s) that can be shown to be approx. 33s. Later attempts by me I suspect were faster but I did not measure them. In addition the afternoon session was given over to passenger rides.

The key number is in the bottom rhs as this equates to a real lap time.

The data can be imported to RaceRender: http://youtu.be/Z9s3z83nGKU

Enjoy!

Camera mount on a vvt track car

I purchased a GoPro 3+ black edition. This went fine until I tried to mount the GoPro on the rear roll over bar. This is the location to put a camera which helps tell you most about your driving skills or otherwise. The roll over bar is just above head height.

When I mounted the camera there for the first time the internal clock got scrambled and the MP4 files were corrupted. Any  images that were produced where very shaky esp about the resonance point of the Sylva vvt engine at 2500rpm. This is a well known problem of the Ford Sigma vvt when fitted with a fast road cam.


I purchased a helicopter GoPro camera mount kit (from the model aircraft industry) via flea bay. I modified it based on experience and if the truth be told without a resonance analyser and knowledge of such I wish not to comment further about the design. I added further damping to remove a resonance of the mount about 2Hz. I also added springs to get more range out of the suspension.

The roll bar part of the mount was fabricated out of motorbike fork mounts for fog lights, indicators etc.

The mount is basically two cross shaped pieces of flat plastic with air filled rubber mounts. I added the springs to preload the rubber and the foam in the middle to damp it down a bit.

Examples

Here is an example of the final design

http://youtu.be/ZGD5Sug_OyQ

Here is an example of the part developed design without springs and dampers.

http://youtu.be/gkc5I6ia20I

Integrating time and video

Tutor PC application

The tutor PC application video can be viewed at:Tutor GPS unfortunately (as purchased) the PC software and the firmware in the unit have several issues not currently resolved by Sumomoto.

1) The files produced by Tutor GPS hardware appears to have corruption in the output file such that Tutor PC application will not display the data correctly. Here is an example of one row of corrected data.

$1752236,

A

,55518306

,-3494917,

1.64,

B9@00B4002400DC,

00AAFFF000A7,

0093004A0109,

00D1FFB20083,

007D008A00F9,

00B9FFAB00D9,

0071009000F6,

00D3FF8300D5,

00BD009D0089,

006F003300FA*

a) $1752236 is a time stamp of the form HH/MM/SS.S ("$" is a start of line character and "*" is end of line character and  "," is a column separator that should be ignored)
b) A denotes a valid set of results V if not
c) 55518306 is the Latitude
d) -3494917 is the Longitude
e) 1.64 is the MPH speed
f) B9@00B4002400DC is broken down as follows:
    i) B9 is something to do with satelites perhaps does not change a lot but only slightly
    ii) @ is a separator
    iii) 00B4 is Hex altitude G forces
    iv) 0024 is Hex Axiel G changes
    v) 00DC is Hex Radial G Changes.
h) 00AAFFF000A7 to 006F003300FA 10x 12byte words which have no discernible effect on Tutor PC application.

The data before correction looks like this

$1752236,

A

,55518306

-,3494917,

1.64,

B9@00B4002400DC,

00AAFFF000A7,

0093004A0109,

00D1FFB20083,

007D008A00F9,

00B9FFAB00D9,

0071009000F6,

00D3FF8300D5,

00BD009D0089,

006F003300FA*

Outstanding problems with Tutor

* The error (as shipped to me) appears (if you ignore start of line and column separators) is with the 17th character it is slipped (on line one only) by two.

* The memory card I used is 4Gbyte when I used a 16Gbyte card no files were stored.

* The problems that remain are with the PC application. It will not allow me to change the split times as per their video referenced above.

I have contacted the factory but so far I have had no response to my issues.

Race Render

There are several free PC applications, that I know about, that do much more that Tutor and one of them is called Track Chrono and the other is called Race Render. Both applications are good, Track Chrono will work with certain GPS 10Hz devices and produce the data on your phone for immediate analysis. I am not into pissing about with USB leads and mobile phone at the track side so the Track Chrono route is not that attractive to me. I want to press a button at the start line and bingo so Tutor GPS and Race Render is the route for me.

Race Render is a wonderful free PC application that will accept Track Chrono formatted input files and integrate your data and video in a combined display for producing custom video of your track day activities.

PC Notepad

Open the Tutor GPS .txt file in Notepad, now at the very least correct the error in line one then you can at least get the Tutor PC application to open the file and display the track. You will then come across the bug that will not allow you to change the split times.

Open Office spread sheet

Next import the corrected file into my special spread sheet and save the Track Chrono (layer tab)in my special .CSV formatted spread sheet. Remove all the data before the speed builds to 1mph (that must be the start point. Similarly remove all the data when the speed falls below 1mph (as you are probably in the paddock). If you mail me your address I will send you a copy of the sheet in open office format .ods

GoPro3+
The key to producing consistent data of your track day activities is the video. I have pi???d about with numerous cheap cameras and I could fill a bucket with the failed examples. The GoPro3+ is the dogs bollocks for motor sport and can come with a wifi dongle waterproof controller. The dongle has a small display that tells you everything about the camera and can be mounted on your dash. One press just before the start line and one press on Tutor GPS and off you go. At the end of the sprint line and safely in the paddock and you can save your GPS and GoPro files for safe keeping. These can be Synchronised in your PC later.

 Here is an example of the integrated result:

http://youtu.be/MmZyk8-DNB8


Since I posted that video I have corrected the G display and sorted out the correct position for the finish line.

Initial purchase

I have been tracking my cars for a couple of years now and this year I decided to take up Hill Climbs and sprints. I want to add some analysis of my activities so I decided to buy a GPS Lap Timer.

Budgets are tight so I have been looking at what is available and came across a product called Pit King GPS and is marketed by JJC and Demon Tweeks in the UK at £150 + VAT + Delivery. I subsequently found out this is an OEM product from Beijing China called Tutor GPS lap timer from a company called Sumomoto and can be purchased via Paypal for $180 inc delivery.

The product is a no nonsense GPS lap timer with all the software either provided or built into the firmware in the unit. It has a 10hz GPS resolution and produces a csv formatted file in a memory card. The basic data is Time stamp, Position XYZ, Speed and acceleration X,Y,Z.

The built in firmware needs to learn the track with a dummy run to define the Start/Stop point in the track. After that all the subsequent runs are referenced to that. The PC application depends on the previous adherence to the process.

Sprints and hill climbs are not always a loop. Forrestburn track of 1030m is no exception. I decided to take the Tutor GPS to a test/track night at Forrestburn to try it out. I did not analyse the data while at the track night but merely downloaded it when I got home. With  a lap top and some knowledge of the file that Tutor GPS hardware produces it is possible to extract the data you want.

As predicted the Tutor hardware display was very little use to analyse the data on track but importing the data to Open Office reveals some hidden treasure. I cannot see at this point doing this at the track side esp in the rain.

The key to using Tutor GPS hardware on a sprint is to Cycle the power every time as this is the only way I have found to reset it for my purposes. Then press the up/down buttons simultaneously such that the top left lap display reads 00.Then as you are about to set off for a timed run press Start/Stop once, the timer should start to display duration numbers. At the end of the run press Start/Stop again. At this point press up/down buttons simultaneously to save the file.

Here is the initial results.

Forrestburn by GPS

Distance vs time

Speed vs time

The above inconsistency is brought about by a poor decision by me to place the ariel away from any metalwork of the car.

References

Sumomoto: http://www.sumomoto.com/GPSLapTimers/index.html

Demo Tweeks: http://www.demon-tweeks.co.uk/karting/lap-timers/pitking-products-gps-lap-timer

Forrestburn track: http://www.mscc.org.uk/forrestburn/track-layout