RoboSavvy Forum

Crust Crawler Current Measurements

2012-11-18T13:11:42+01:00

Here is the filtered current measurement,
shunt 90mOhms in negative power supply line, all servos.
Servos at rest ~ 322 mA
Servos average ~ 1.5 A
Servos peak ~ 5A
Friedrich
[img]http://robosavvy.com/Builders/FriedV/cur3.jpg[\img]

Statistics: Posted by FriedV — Sun Nov 18, 2012 1:11 pm

Crust Crawler Current Measurements

2012-11-18T11:10:58+01:00

Shunt is across all servos, in the negative supply line from the LiPo 3S.
Resolution of the red graph is +-1V, time res <10msec.
I cannot say anything about impact & torque.
I'll try to take some further measurement with filters.
Friedrich

Statistics: Posted by FriedV — Sun Nov 18, 2012 11:10 am

Crust Crawler Current Measurements

2012-11-16T20:12:46+01:00

the shunt is measuring across all servos or one servo ?

what resolution is the graph ?
can you identify impact and torque?
can you run a kalman or other non delay filter on the signal ?

Statistics: Posted by limor — Fri Nov 16, 2012 8:12 pm

Crust Crawler Current Measurements

2012-11-15T17:13:20+01:00

Here are two pics of Crustcrawler AX18 current measurements.
The blue line ist the data channel, only used for trigger purposes here.
The red line is the total servo current measured as a voltage across a 90 milliOhm resistor in the power line. First pic is sitting on my test bench legs moving free, second is Crusty on the ground. Less difference than I expected in current need. Program executed is Belly Dance fron Testbench.

Friedrich
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Statistics: Posted by FriedV — Thu Nov 15, 2012 5:13 pm