1
Download OPERATION MANUAL Position Control Units - Support
Transcript
Section 10-4 Torque Limits Positioning that Does Not Reach Target Position (Example: Pushing a Load) ABSOLUTE MOVEMENT (word a, bit 03) Forward Rotation Current Limit Designation Bit (word a+16, bit 14) When position deviation has accumulated due to pushing, torque in the pushing direction that is greater than the limit value will be generated if the forward rotation current limit is cleared, which may result in damage to the device. Therefore, specify a torque limit in the pushing direction also when starting operation in the opposite direction. When positioning is not completed and the position deviation due to pushing remains, the axis's Busy Flag will remain ON until DECELERATION STOP or This flag remains ON for the time the output torque is limited by the limit value. other stop operation is executed. Receiving Command Flag (word b, bit 00) Busy Flag (word b, bit 13) Torque Limit Status Flag (word b+1, bit 09) Position Pushing direction target position (position command value) Solid line: Command present position Pushing stop position Broken line: Feedback present position (Servomotor's actual position) Speed Time Solid line: Command speed Pushing direction target speed (speed command value) Time Broken line: Servomotor's actual speed Position deviation Start Pushing Start in opposite direction Time Time in which accumulated position deviation is consumed a = Beginning word of Axis Operating Output Areas specified in Common Parameters + (Axis No. −1) × 25 b = Beginning word of Axis Operating Input Areas specified in Common Parameters + (Axis No. −1) × 25 Note 362 In applications such as pushing a load, when using the torque limit function to limit the output torque of the Servomotor and stop the machine, the command present position reaches the target position while the feedback present position does not, which causes the pulses to accumulate for the position deviation in the Servo Drive’s deviation counter. To change movement to the opposite direction, send the operating command with the Current Limit Designation Bit setting enabled in the pushing direction. If the Current Limit Designation Bit setting is disabled for the direction in which the load is being pushed when operation is started in the opposite direction (i.e., an operating command is sent without specifying the torque limit), torque will be generated in the pushing direction at the start of operation. This is due to the position deviation accumulated in the pushing direction and may result in damage to the machine or an accident.
