I have max. motor temperature on A5 and I want to regulate ventilation (cooling) in robot cell. How can I monitor temperature on motors?
I have found only $PHGTEMP but it is temperature inside KCP.
Monitoring motor temperature
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Vlad222 -
November 14, 2016 at 8:21 AM -
Thread is Resolved
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A5_temp_degC= $MOT_TEMP[5]-273 ; subtract offset
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A5_temp_degC= $MOT_TEMP[5]-273 ; subtract offsetThank you, panic mode!
I have another one question...Where can I find variables - max. temp. (limits) on motors?
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A5_temp_degC= $MOT_TEMP[5]-273 ; subtract offset273? Oh good grief, they calibrated the temperature reading to the Kelvin scale?
Personally speaking, I never found the "zeroing" on those values to be very good -- the temperature variations across the motors on a robot that had been sitting still for 12hrs were just too big. But the deltas were pretty reliable, from what I could see.
I was doing tests for the affects of thermal expansion on robot accuracy, and so to establish our baseline I ensured the test robot sat unmoving and unpowered overnight for at least 12hrs, so that all the motors were at ambient. Then I ran a test program that worked the robot very hard (a KR500 with a ~400kg steel block mounted to the A6 flange, running every axis at 100% speed and acceleration) for 8-12hrs, and logged $MOT_TEMP periodically, along with triggering a metrology system that measured the robot's accuracy at multiple points. Then we correlated the accuracy errors to the temperature changes.
Which is a long-winded way of saying, you may want to check the accuracy of your $MOT_TEMP values by establishing what each motor reports at a known temperature. If you check $MOT_TEMP when the robot has been sitting still overnight, before applying power to the motors, and compare those values to the ambient air temperature near the robot at that moment in time, you should obtain a reasonably accurate per-axis offset (in addition to the 273deg Celsius-Kelvin difference) that you can use long term.
OTOH, the accuracy of $MOT_TEMP may have improved since I did that experiment (which was nearly 10 years ago, now), so going this extra mile may not be necessary.
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273? Oh good grief, they calibrated the temperature reading to the Kelvin scale?
Personally speaking, I never found the "zeroing" on those values to be very good -- the temperature variations across the motors on a robot that had been sitting still for 12hrs were just too big. But the deltas were pretty reliable, from what I could see.
I was doing tests for the affects of thermal expansion on robot accuracy, and so to establish our baseline I ensured the test robot sat unmoving and unpowered overnight for at least 12hrs, so that all the motors were at ambient. Then I ran a test program that worked the robot very hard (a KR500 with a ~400kg steel block mounted to the A6 flange, running every axis at 100% speed and acceleration) for 8-12hrs, and logged $MOT_TEMP periodically, along with triggering a metrology system that measured the robot's accuracy at multiple points. Then we correlated the accuracy errors to the temperature changes.
Which is a long-winded way of saying, you may want to check the accuracy of your $MOT_TEMP values by establishing what each motor reports at a known temperature. If you check $MOT_TEMP when the robot has been sitting still overnight, before applying power to the motors, and compare those values to the ambient air temperature near the robot at that moment in time, you should obtain a reasonably accurate per-axis offset (in addition to the 273deg Celsius-Kelvin difference) that you can use long term.
OTOH, the accuracy of $MOT_TEMP may have improved since I did that experiment (which was nearly 10 years ago, now), so going this extra mile may not be necessary.
SkyeFire, Thanks a lot for info of accuracy!
I have error KSS26018:
"Ackn. Max. motor temperature exceeded (A5)" (in the picture).Where can I find what temperature is max for A5 and other axes?
I want to check $MOT_TEMP all time and if it is close to max - for example reduce speed or something similar.
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Hi Vlad
Can you tell me what value is displayed after putting the variable $MOT_TEMP[5]
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$MOT_TEMP[x] displays the current temperature of servo motor 'x'. However, this temperature is not very accurate -- it's good enough for tripping the over-temp error, but the 'zero' may be incorrect by several degrees.
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Good monrnig for all.
I am reading KRC2 System Variable, trying to find some Motor Temperature variable. I didn't find it.
Some of you have already tried to use the same variable of KRC4, $MOT_TEMP[x] to read motor temperature in KRC2?
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Should be the same variable, IIRC. That's the one I recall doing some thermal data logging with on KRC2s, several years ago.
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Thank you SkyeFire, I will have to send thermal and torque data to a PLC in some words. I Tested in KRC2 OfficeLite and the variable $MOT_TEMP[x] seens work.
Thankyou.