1.Torque - torsion angle relation coordinate system

Method of specifying the horizontal axis as the torque value coordinate (in N.m) and the vertical axis as the torsion angle value standard (in arc. min)

2.Hysteresis curve

The robot uses a precision reducer to fix the input end, and at the output end, it is first loaded in reverse to the rated torque (or alternatively, it can be loaded in forward direction to the rated torque). Starting from the torque value and torque angle value at the rated torque point at this time, the load is uniformly reduced to zero, then uniformly loaded in forward direction to the rated torque, then uniformly reduced in reverse direction to zero, and finally uniformly loaded to the reverse rated torque point. During this process, the obtained torque values and the points formed by the torsion angle values are sequentially connected to form a graph.

3. Torsional rigidity

select the evaluation interval on the hysteresis curve, subtract the difference between the end torque value of the evaluation interval and the starting torque value of the evaluation interval, and the ratio of the difference between the torque angle value corresponding to the end torque point of the evaluation interval and the torque angle value corresponding to the starting torque point of the evaluation interval.

4.Gear clearance
On the hysteresis curve, the difference between the torque angle value at the output end of the precision reducer used by the robot during the process of reverse uniform cutting and reverse uniform cutting when the load is 0 and the torque angle value of the measured precision reducer during the process of forward uniform cutting and forward uniform cutting when the load is 0.
5.Invalid distance

On the hysteresis curve, the average value of the torque angle at the output end of the robot's precision reducer when uniformly applied to 3% of the rated torque in the forward direction and uniformly reduced to 3% of the rated torque in the reverse direction is subtracted from the average value of the torque angle at the output end of the tested precision reducer when uniformly reduced to -3% of the rated torque in the forward direction and uniformly loaded to -3% of the rated torque in the reverse direction.
6.Positioning error

The difference between the theoretical arrival at the designated position and the actual arrival at the designated position and the return to the starting position when the robot uses a precision reducer to perform reciprocating rotational motion.
7.Repetitive positioning accuracy

Under the same conditions, when the robot uses a precision reducer output shaft to perform reciprocating rotational motion, the range of consistency obtained from reaching the specified position and returning to the starting position using the same program to its continuous results.

8.No-load repetitive positioning accuracy

Under the same conditions, when the robot uses a precision reducer output shaft to perform reciprocating rotational motion without load, the range of consistency between the continuous results obtained by applying the same program to reach the specified position and returning to the starting position.

9.Load repetitive positioning accuracy

Under the same conditions, when the robot uses a precision reducer output shaft to perform reciprocating rotational motion under load, the range of consistent results obtained from reaching the specified position and returning to the starting position using the same program.