A New Position Detection and Status Monitoring System for Joint of SCARA

High-precision position detection of joint and status monitoring of speed reduction gearbox (SRG) are two key technologies in the research and development of selective compliant assembly robot arm (SCARA). The existing schemes have some problems, such as the large occupation of space, high cost, complex implementation, lack of status monitoring, etc. Therefore, first, in order to get the accurate position information of joint when the SCARA is powered up at the first time, a new combined incremental encoder with unevenly distributed multiple indexing signals and initial position detection method is proposed. Second, in order to get the accurate position information and monitor the operation status of the SRG during the positioning operation, a real-time position detection and status monitoring method based on the transmission error using dual incremental encoder is proposed. The general design principle has been given, and various experimental results have confirmed the effectiveness of the proposed solution. The proposed new combined incremental encoder has the advantage of small occupied space, easy realization, and low cost. The proposed position detection and status monitoring method not only realizes the high-precision detection of the joint position but also provides the key data for the monitoring of the running state of the SRG.