| dc.description.abstract | The Serial Measuring Unit (SMU) is a component used to measure motor angles in robot joints
at ABB. Currently, the SMU is under development, and ABB has to manually test the SMU
to ensure that changes to the software or hardware do not unintentionally introduce bugs or
break previously working features. This testing process is time-consuming and unreliable.
This thesis presents the development and implementation of an automatic test system for
the SMU in ABB’s existing testing environment. The developed automatic test system is an
attempt to utilize open-loop control to test functionalities and the quality of angle measurements. A Resolver Test Unit, primarily consisting of a stepper motor and seven resolvers,
was designed for this open-loop test system. Test scripts were developed to control the stepper motor and read data from the SMU. Upon analyzing the results, it became evident that
the automatic test system lacks the required accuracy and precision to execute high-precision
angle measurement tests reliably. Additional testing revealed a non-linear stepping pattern
in the stepper motor and a wrongly tuned stepper motor controller. Furthermore, a slight
deviation in the mechanical parts of the Resolver Test Unit is suspected, further affecting the
resolver measurements.
The test system performed consistently well for tests that did not involve high-precision angle
measurements. However, the test system does not qualify for angle and quality measurement
tests with the current hardware for open-loop control. Thus, the test system must either be
upgraded to higher-quality hardware or changed to a closed-loop system. In addition to one
of these requirements, the system needs to be calibrated. | |
