shane Posted July 22, 2021 Share Posted July 22, 2021 In Ver 2.6.1 firmware , it have two parameters for static friction compensation, is there a notes about how to tune Motor[x].Servo.Ksff and Motor[x].Servo.SffCycles ? Link to comment Share on other sites More sharing options...
Eric Hotchkiss Posted July 30, 2021 Share Posted July 30, 2021 This is described in the latest version of the Power PMAC SRM and Users Manual. You can get them from your local Omron technical support or download it from the US website available here. https://assets.omron.com/m/76e3f5e50c46e0e9/original/Power-PMAC-Software-Reference-Manual.pdf https://assets.omron.com/m/2c1a63d391d6bfa3/original/Power-PMAC-Users-Manual.pdf Basically we add Motor[x].Servo.Ksff to the servo loop output for Motor[x].Servo.SffCycles servo cycles to break free from static friction. Link to comment Share on other sites More sharing options...
shane Posted August 7, 2021 Author Share Posted August 7, 2021 Hi Eric How can I kown how big this value should be, is there a recommend move to test it ? Link to comment Share on other sites More sharing options...
Eric Hotchkiss Posted August 13, 2021 Share Posted August 13, 2021 I haven't used them, but I would try parabolic or point to point tune moves. Does your system have stiction? Link to comment Share on other sites More sharing options...
shane Posted August 16, 2021 Author Share Posted August 16, 2021 yes , if push the motor by hand,it's clearly the static friction will be larger than Coulomb friction Link to comment Share on other sites More sharing options...
Eric Hotchkiss Posted August 17, 2021 Share Posted August 17, 2021 You might try using the open loop test with a single iteration to look for the smallest value that makes the motor moves. This can be taken as the sum of Motor[1].Servo.Kfff and Motor[1].Servo.Ksff . If PMAC is sending an analog signal to the amplifier, you would want to make sure the DAC bias is calibrated first. Another option would be to try Parabolic or point to point tuning moves and look for low initial following error. Point to point tuning moves in the newer IDE versions are jog like moves. In older IDE versions they may be replaced with trapezoidal and S-Curve tuning moves. Link to comment Share on other sites More sharing options...
Eric Hotchkiss Posted August 23, 2021 Share Posted August 23, 2021 open loop percent times max dac Just to be clear, the size of the dac output is the percent from the open loop test times Motor[x].MaxDac, so if you want to go the route of finding a value that barely moves the motor. Motor[1].Servo.Ksff = (Open Loop Percent) * Motor[x].MaxDac - Motor[1].Servo.Kfff Link to comment Share on other sites More sharing options...
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