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UbiquityRobotics / magni_robot

Starting point for Magni Robots. Includes launch files and configuration.
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BMS #83

Open pyhuang2011 opened 5 years ago

pyhuang2011 commented 5 years ago

Have a BMS according to regulation(should let the system know over current/over temperature...) at least know is it charging.

davecrawley commented 5 years ago

Please point to the regulation you are referring to or give a comprehensive description. Over temperature detect is necessary for LiIon batteries due to their tendency to catch fire. Temperature is much less significant for Pb Acid

pyhuang2011 commented 5 years ago

there are 2 parts, one is a general description in regulation when you have issues related to safety you should stop the machine, I think over current and over temperature is. - need to know and record for diagnose. the other is we want the robot to know it is charging so it can disable Movement，unless human remove the charging plug

davecrawley commented 5 years ago

Well we have temperature measurement in the hardware which we can probably expose - so let's do that - it will take some time. Current measurement is in there too - we should expose that too.

pyhuang2011 commented 5 years ago

so if you define discharge current is -xxx A, then charge current is + xxx A

davecrawley commented 5 years ago

That's not quite how the current sensing works. It detects current being used by the robot systems not net current in to the battery. In charging, the robot will still show power consumption even if some of this current comes from the charger rather than the batteries.

As such

The other thing that's important is that the charger boosts the voltage quite a bit - again the is Pb-acid not LiIon so the voltage jump is significant and is probably the easiest way to detect the event of being plugged in. In fact you could write the voltage to non-volatile memory every say 10 seconds and compare against that. That way even if the robot was shut-down accidentally during charge up the system would be able to tell.

David

David

On Wed, Mar 13, 2019 at 9:39 PM pyhuang2011 notifications@github.com wrote:

so if you define discharge current is -xxx A, then charge current is + xxx A

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