David Bar
@observie
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In software development, we live by Donald Knuth's "premature optimization is the root of all evil" approach: start simple, profile, then optimize. I believe it applies to hardware too - but boy - when software breaks, it just means rewriting a few lines, whereas hardware
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Another GIM6010-8 gets quite hot while idle: 51.4°C (124.3°F). Others are reasonable, some even quite cool, but overall thermal performance among the 12 motors is inconsistent (see attached 12 measurements and graph by @grok). At the very least, redundantly hot motors mean the
One GIM6010-8 motor gets crazy hot just sitting idly: around 50°C (122°F) for doing nothing. All others remain calmly cool.
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An interesting approach to PD tuning for RL from @ChongZitaZhang:. - very high P gain, in the hundreds.- let RL do the magic.- 50Hz control loop. Result:. Thank you Chong Zhang ❤️.
@observie very big gains, hundreds. RL does the magic.
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My AI friend wants me to read these two, claiming that "Åström/Murray's "Feedback Systems" kicks off with killer basics on PID + FF for actuators like yours, showing how velocity/torque FF cuts errors in joint positioning without PID strain—super relevant for smooth quadruped
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Pure gold from @KyleMorgenstein . Setting soft PID gains would allow an RL policy to achieve compliance, if needed, and when not, the policy can always exaggerate commands (e.g. by setting position values beyond their targets), and then rapidly adjust, based on realtime feedback,.
@observie for RL you want to use gains so soft it couldn’t support the robot’s weight under gravity. for model based control double the P gain. you should not have to adjust the PD params at runtime. run the PD controller as fast as you can (I’ve seen up to 40kHz) and interpolate commands.
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Impressions after spending a Saturday with RoboDog. 1. Motors' behavior under load is a whole new ball game. 2. A position command that easily sends an unloaded motor to the desired position behaves completely differently when motors are loaded. 3. This is amplified when.
RoboDog is standing for the first time!. Look daddy, no pillows 🙂. All 12 motors are online, periodically sending their position estimates via CAN. A control user space Rust application is monitoring the motor positions, and sending them position commands.
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