Tom Caradoc-Davies

SAM Development at the Australian Synchrotron
Presenter Tom Caradoc-Davies & Mark Clift, Australian Synchrotron
The SAM robots at the Australian Synchrotron are key components of the beamlines, allowing automated sample exchange and remote access. A development project has been carried out to improve the robot systems with goals of increasing reliability and stability. This program has been carried out in a phased approach with the first phase (upgrading the robot hardware to the latest Epson G6 series of Scara robots) already implemented on both MX beamlines. Using the new capabilities of the robot, an EPICS interface has been created to provide low-level control over the robot. The EPICS interface can run at the same time as the traditional DCSS/BluIce system, and provides a way for staff to recover from error without requiring Epson software and losing probe information. The second phase of the project will involve a new python middleware layer (under construction), which uses EPICS as the interface to the robot. The python middle layer will eventually replace the robot service. As part of phase two the non-robot mechanical systems are being evaluated for possible engineering changes that could lead to increased stability and reliability.
Long term issues with force sensing have been identified and repaired in a novel way. Force measurements now have a peak-to-peak noise level that is 10 times lower than that achieved historically and the time required to obtain a measurement has dropped by a factor of 5. The improved force sensing has halved the time required for robot calibration. Also the robot touches physical components more softly and bracing of some components, such as the mini-kappa, is no longer required during calibration. The new force sensing system is a purely software implementation, the original force sensor hardware has not been changed. The changes to the robots have significantly reduced the failure rates of the SAM robots, increasing productivity and reducing workload for beamline staff.