Thursday, 4 October 2012

Android app for speed measurement.

OK, I admit it, I am a gadget freak. I should attend the nearest Gadge-a-holics anonymous meeting room. I just love technology and I am always looking for ways to use information gathered from gadgets to apply to our boating adventures. 

In a previous posting we looked at pointing the TV antenna for best performance for digital reception depending on your geographical location. Click Here to view.

In another previous Android apps posting I did a bit on coastal tides and their effect upon rivers. Click Here to view.  When dealing with tidal rivers, it also pays to consider the weather and the amount of water flowing down stream.

In the last Android apps posting, I did a bit on the weather apps for android smart phones. Click Here to view. Today, I thought I would look at the "need for speed" and slowing down after life spent in a layby watching those in the fast lane go by!

How fast does your boat move?

Most boats don't come with a speedometer fitted. The ones that do usually measure the speed in knots. The inland waterways have a speed restriction set, which can vary a bit from place to place and canal or river. However, as the lifestyle is intended to be conducted at a tad over standing still. It could be useful to have a speedometer fitted to your boat. 

However, there is one fitted to many boats its the revolutions counter on your engine. There is also  another one on your android phone. If you can marry the two together then you can create a speed with reference to engine revolutions chart. 

Beta 38 Engine Data
I use an android application called Speedometer which uses the GPS satellite system to measure our speed and distance travelled. Over a set distance I measured the GPS speed at different RPM settings. Using a distance of one mile. I did a quick calibration of engine revs against boat speed over the ground - or in our case over the water. 

I did this on a nice wide, straight, stretch of deep water on the Aire and Calder navigation. I chose a day when there was no wind to skew the readings. The sand and gravel barges do well over our top speed along this waterway. 

As a starting point, I took the Beta Greenline power/RPM/torque tables. I have now created a second plot on the table recording our speed against the engine revolutions for Rosie. 

Next time Rosie comes out of the water for blacking I shall be refitting the original propeller again (which has had the pitch changed) and I will be able to make a new plot and compare the changes made. 

I still believe that engine speed should not be set at a waterways speed limit. The engine speed should be set depending upon the prevailing conditions. Such as when passing moored boats or if creating a breaking wave. In these conditions you should slowdown. 

I already have a rough idea that the engine when run at our cruising speed (1,200 - 1,400 RPM) uses around 1 litre of diesel an hour.  So being a gadget freak - it soon had me thinking about how I could use an android application to check.

I have created a poll that will run between now and the 1st of January 2013. It's not very scientific. Its a simple question "Will CART Succeed". You have three choices Yes, Unsure and No. Now you can vote for one of the three choices. If you change your mind before the poll closing date. You can come back and change your vote. (I wish we could do that for politicians) You will find the poll option on the right hand side just below the members pictures.


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