LBT Q Engineering Review Primary Mirror Cells Biddick/Gusick/Kern

13-Jan-2009LBT Q42008 Eng/SW Review Accomplishments (Q4/2008) Installed bit bounce buffer board at SX, HP-1 and found that it did not solve the problem. (CB, MG, JK) Installed bit bounce buffer board at SX, HP-1 and found that it did not solve the problem. (CB, MG, JK) Additional study revealed an enable signal timing problem with stepper controller, fixed by Chris in software on mountain. (CB, MG) Additional study revealed an enable signal timing problem with stepper controller, fixed by Chris in software on mountain. (CB, MG) Also removed acceleration/deceleration profile which led to smoother, deterministic operation (no missed steps). (CB, MG) Also removed acceleration/deceleration profile which led to smoother, deterministic operation (no missed steps). (CB, MG) Purchased and tested new micro-stepping motor controller. (MG) Purchased and tested new micro-stepping motor controller. (MG) VHDL algorithm written and tested for microstepping using existing software control. Future velocity mode control also partially simulated/tested. (MG) VHDL algorithm written and tested for microstepping using existing software control. Future velocity mode control also partially simulated/tested. (MG) New hardpoint monitor board design underway using incremental and absolute encoders, new microstepping motor controller, and optional servo motor support. (MG) New hardpoint monitor board design underway using incremental and absolute encoders, new microstepping motor controller, and optional servo motor support. (MG) Replaced two non-functioning fans in spare VME crate. (GH) Replaced two non-functioning fans in spare VME crate. (GH) Telemetry has been implemented in the PMC subsystem, but is still turned off due to performance issues. (CB) Telemetry has been implemented in the PMC subsystem, but is still turned off due to performance issues. (CB) The elevation angle is sent to VxWorks in a way that is more robust with respect to load on the server running the PMC. (CB) The elevation angle is sent to VxWorks in a way that is more robust with respect to load on the server running the PMC. (CB) PMC documentation review comments completed. (DA, MG, JK) PMC documentation review comments completed. (DA, MG, JK)

13-Jan-2009LBT Q42008 Eng/SW Review Highlights (Q4/2008) Much PMC electronic re-work occurring in Tucson Much PMC electronic re-work occurring in Tucson Cells still behaving well Cells still behaving well

13-Jan-2009LBT Q42008 Eng/SW Review Open Issues Technical Technical Cell Documentation a work in progress, 08-Jan review created final (hopefully) list of AIs. Cell Documentation a work in progress, 08-Jan review created final (hopefully) list of AIs. Hardpoints have lower stiffness than desired, meet 80N/ m (min required) Hardpoints have lower stiffness than desired, meet 80N/ m (min required) Actuator test stand undocumented/not maintainable Actuator test stand undocumented/not maintainable Tracker reveals hysteretic behavior (~5u) in hardpoints Tracker reveals hysteretic behavior (~5u) in hardpoints Schedule Schedule Major PMC changes, replacing hardpoints with super-hardpoints, and redesigning HP monitor board and steppe driver must be completed this Quarter if we hope to re-fit the PMCs next shutdown. Major PMC changes, replacing hardpoints with super-hardpoints, and redesigning HP monitor board and steppe driver must be completed this Quarter if we hope to re-fit the PMCs next shutdown. Financial Financial ETS Test Stand proposal will be cost-plus, >$140k ETS Test Stand proposal will be cost-plus, >$140k Resource Resource Mountain staff limitations pace work at Observatory Mountain staff limitations pace work at Observatory ETS staff limitations pace cell documentation effort ETS staff limitations pace cell documentation effort

13-Jan-2009LBT Q42008 Eng/SW Review Planning (Q1/2009) Mike G. continues modification of hardpoint monitor board Mike G. continues modification of hardpoint monitor board Telemetry has been implemented in the PMC subsystem, but is still turned off due to performance issues. (CB) Telemetry has been implemented in the PMC subsystem, but is still turned off due to performance issues. (CB) Super-Hardpoint 1 st article to be built and characterized. Super-Hardpoint 1 st article to be built and characterized. ETS will rework Actuator Calibration Stand (TBD) ETS will rework Actuator Calibration Stand (TBD)