Live Tachograph Data Part 2 - Looking for a Heartbeat
Wednesday 25th August 2021
Guy Reynolds, the co-founder of Aquarius IT, goes into more detail here about using live tacho data, the pitfalls and why ClockWatcher Elite cleverly looks for a 'heartbeat'.
As I mentioned in part one, live data for me is the signal that comes out of the back of the tacho.
Each time the driver activity changes (drive, other work, period of availability and break), the tacho will send a simple signal out of the back of the tacho, to say there has been a change of activity. Simple enough you might think?
So, to work out how long a period of activity lasts for, we simply need to wait until the next change of activity signal is transmitted out of the back of the tacho and then we just need to work out the amount of time between activity changes, correct?
However, before we can try to work anything out there are a number of hurdles to jump first. The first thing we need to understand is how the activity change is time stamped. In simple terms, we need to identify if each activity change is stamped with tacho time or GPS time.
If the download device is time stamping with tacho time, this is generally good news. If the data is time stamped with GPS time this is generally problematic to making live data show what is on a driver's card... here's why....
The problem with all this is the original specification for the EU tacho specified how and when a signal for an activity change will be transmitted out of the back of the tacho... that is as far as the EU specification goes.
Therefore, from our point of view, because the software is mimicking the tacho calculation for the dominant activity every minute, the way the data is stamped is of crucial importance when we are presenting the results to a customer. The tacho is working to the second, but as far as activity changes are concerned the tacho will present activity as whole minutes. It is possible to have 60 activity changes every minute, but only one activity will be dominant; hence, when we are mimicking the tacho, we need to add up all the activity changes in a minute and work out which one has the greatest number of seconds (dominant activity).
This is further complicated if the data is time stamped with GPS time and the time set on the tacho is out by a minute or even a few seconds. This will affect the perceived accuracy of the live data when comparing it to reading a driver's card. This is because it can affect the dominancy of an activity for any given minute. This will best be shown if a driver is operating in congested traffic or performing multi drop activities.
Another problem area with live data is that the tacho only sends a signal out of the back when there is an activity change. There is no constant signal to tell you what the tacho is doing 'now' in real time. There is only a signal when something changes. Why is this a problem?
Let's say at 10.00am in the morning the tacho signals a change in activity to driving, which is remotely transmitted to us. Then at 10.30am the vehicle goes into a remote area of the country, with no mobile signal. At this point unless we do something different (a little cleverer), as far as we know the vehicle is still live and in driving mode. At 11.00am the driver pulls over to take a break, then carries on for 30 minutes to a delivery point, where the driver is then performing a mixture of POA and other work for 60 minutes. At this point it could be around 1.00pm with many changes of activity, but as part of the central processing is concerned the vehicle is still in driving mode from 10.00am. The transport planning team will be making decisions based on information that may not be complete, because there has been no mobile signal for a number of hours.
What do we (ClockWatcher Elite) do to make sure this does not happen?
We have a number of methods, depending on the remote downloading equipment, but in simple terms we look for a heartbeat from the remote downloading equipment (is it still alive). If we cannot see a heartbeat, we will mark our screens in a different colour so that whoever is looking at the information in real time, knows this may not be up to date.
It may sound here, that I am talking down the value of live feed information, but I'm not at all. Live feed can add great value to the right transport operation, as I explained in part one with the 'Friday afternoon' example. What I am trying to explain is that there are a number of software companies out there that say they can show live data from the tacho, BUT it's not always that straightforward and operators must be aware of the pitfalls in dealing with live data.
If you think live feed data is service for you, then look no further come and talk to us Contact us