YASKAWA UAK series User Manual

Contents

YASKAWA UAK series User Manual Manual pdf 208 page image

9.1 Type of Adjustments and Basic Adjustment Procedure9-7 Adjustments99.1.4 Safety Precautions on Adjustment of Servo GainsSet the following protective functions of the SERVOPACK to the correct settings before starting to adjust theservo gains.(1) Overtravel FunctionSet the overtravel function. For details on how to set the overtravel function, refer to 8.4.2 Overtravel.(2) Torque LimitThe torque limit calculates the torque required to operate the machine and sets the torque limits so that the out-put torque will not be greater than required. Setting torque limits can reduce the amount of shock applied tothe machine when troubles occur, such as collisions or interference. If a torque limit is set lower than the valuethat is needed for operation, overshooting or vibration may occur.For details, refer to 8.6 Limiting Torque.(3) Excessive Position Error Alarm LevelThe excessive position error alarm is a protective function that will be enabled when the SERVOPACK is usedin position control.If this alarm level is set to a suitable value, the SERVOPACK will detect an excessive position error and willstop the servomotor if the servomotor does not operate according to the reference. The position error indicatesthe difference between the position reference value and the actual motor position.The position error can be calculated from the position loop gain (Pn102) and the motor speed with the follow-ing equation.• Excessive Position Error Alarm Level (Pn520 [1 reference unit])∗1. The 10th digit of the model number of the servomotor provides information about the encoder resolution.∗2. To check the Pn102 setting, change the parameter display setting to display all parameters (Pn00B.0 = 1).∗3. This coefficient is used to add a margin that prevents a position error overflow alarm (A.d00) from occurring inactual operation of the servomotor.Set the level to a value that satisfies these equations, and no position error overflow alarm (A.d00) will be generatedduring normal operation. The servomotor will be stopped, however, if it does not operate according to the referenceand the SERVOPACK detects an excessive position error.If the servomotor’s maximum number of rotations is 6000 min-1 and Pn102 is set to 40 with an encoder resolution of20-bit (1048576), the setting of Pn520 is calculated as shown with the following equation.CAUTIONIf adjusting the servo gains, observe the following precautions.• Do not touch the rotating section of the motor while power is being supplied to the motor.• Before starting the servomotor, make sure that the SERVOPACK can come to an emergency stop at any time.• Make sure that a trial operation has been performed without any trouble.• Install a safety brake on the machine.Failure to observe this caution may result in injury or damage to the product.Position Error = ×Motor Speed [min ]-160Encoder Resolution*1Pn102 (1/s) *2Pn520 > × × (1.2 to 2)*3Max. Motor Speed [min ]-160Encoder Resolution *1Pn102 (1/s) *2SGMGV-غغغغغغغSymbol Specifications Encoder resolution8 20-bit absolute 1048576