สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) Orbit Control System for Siam Photon Source Accelerator Technology Division Technical and Engineering Division

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 2 The Orbit Stability At Siam Photon Source, for example, during 11 hours of user beamtime period, the fluctuation of the photon beam monitored with a electron beam position monitoring (BPM) is about μm in horizontal and vertical directions, respectively. It is well known that beam orbit stability is one of the quality criteria in synchrotron facilities around the world. 11 hrs

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 3 The Orbit Stability Monitor reading Beam orbit / fluctuation MagnetRF cavityPS output GirdereBPM pBPMVacuum chamber Air temp. (expt area) DIW (BL)DIW (VAC)DIW (mag, rf, ps) Air temp. (STR) Outdoor temp.Machine settingsAC voltage PS electrical heatingCTW / CHW AHUs Synchrotron light Cable heating Propagation chart from the heat source to the fluctuations in the beam orbit and beam size [Chen et al., 2002] The cooling tower water (CTW) The chilled water (CHW) The de-ionized water (DIW) The air handing unit (AHU) Orbit Feedback Control Several detrimental effects lead to beam orbit variation, which include thermal effects, ground vibration, mechanical vibration of accelerator components, among others. The machine group has made considerable effort to control/manage such effects during the past few years.

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 4 Introduction We can clarify that our current BPM problems are: 1.Low quality of BPM cables, i.e. the original cables have high loss rate and one layer of electromagnetic shielding, and 2.The original installation of BPM signal cables in cable trench around storage ring without the cable tray separations. in 2011 Invested: ~908, B. Thank to visiting machine physicists from NSRRC, Taiwan for their helps and suggestions on solving the BPM signal cable problems  Improving eBPM accuracy: A Short History of Progress A Short History of Progress :

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 5 The SPS-STR Orbit Control  The development of orbit control system: where, a linear response matrix (R) describes the action of small changes (  I=[  h,  v]) in the collector magnet fields on the e - beam position (  Q=[  x,  y]) measured at the e - beam position monitors (eBPMs). The system identification/modeling “ …Two eqs. are well known and have been successfully implemented for orbit control at SR facilities all around the world …” In fact, it has been developed by machine group for some time, but cannot be implemented due to inaccuracy of the BPM system.

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 6 The SPS-STR Orbit Control This method could be possible with (strong condition): The dynamic system need to be in the “linear region” (all the time) i.e. environment must be controlled perfectly: no disturbance/noise effects, etc. Linear regionNon-Linear region Example: Y=2X External Disturbances: EMI, noise, temperature, etc. Alternatively, from a control point of view: “…we choose to maintain system performance (tolerant/robust system) rather than control the environment/external disturbances...” This situation leads to the modified idea of “Fault Tolerant Control (FTC)” method.

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 7 Fault Tolerant Control (FTC) Fault Tolerant Control (?): Controller SystemActuator Sensor Reference inputs Actuator faults Process component faults Sensor faults Output A conventional feedback control system “…A conventional feedback control design for a process plant or vehicle system may result in unsatisfactory performance (even instability), in the event of malfunctions in actuators, sensors or other components of the system. In order to overcome the limitations of conventional feedback, new controllers are being developed which are capable of tolerating component malfunctions whilst still maintaining desirable and robust performance and stability properties…” [Patton, 1997]

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 8 Fault Tolerant Control (FTC) The FTC architecture for Siam Photon Source The external disturbances: d(t) acting in a system can be viewed as “specific type of fault signals: f(t) ”, facilitating the use of methods of on-line estimation and compensation theory. Fault Tolerant Control: Siam Photon Source The control re-design block uses the fault information and adjusts the controller to the faulty situation. The diagnosis block uses the measured inputs and outputs and tests their consistency with the plant model. Its result is a characterisation of the fault with sufficient accuracy for the controller re-designs The architecture of FTC (Blanke et al., 2003) Diagnosis Control Re-design Supervision level Execution level ControllerSystem The conventional feedback control design The FTC design

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 9 Fault Tolerant Control (FTC) The FTC architecture for Siam Photon Source The on-line fault estimation and compensation scheme for SPS This can be re-written in simplified as: This shows the concept of the on-line observer-based adaptive controller strategy for on-line estimation and compensation in which A x, C x, K x, K d and L are the designed matrices with stability of both the observer and control elements of this adaptive system (Klinkhieo, 2009). Therefore, the total feedback controller is given by: The on-line fault estimation and compensation can be implemented as the closed-loop system: (1) (2) (3) Fault Tolerant Control: Finally: (4) u x (t) u c (t) u(t) Storage Ring Diagnosis Control Re-design Adaptive PID controller : takes control action based on past, present and prediction of future control errors

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 10 Fault Tolerant Control (FTC) The FTC architecture for Siam Photon Source Controller SPS-STR 28-Steering magnet power supplies Golden orbit References (4x28=112) 20-BPMXs 20-BPMYs (2x20=40) Fault Tolerant Control: In order to study various effects on the orbit feedback performance, the combination of LabVIEW and MATLAB scripts are developed. It utilizes all of the 20 BPMXs, 20 BPMYs, 16 horizontal and 12 vertical correctors.

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 11 Fault Tolerant Control (FTC) The FTC processing algorithms are implemented in a MATLAB code, and communicate with BPM hardware components and correctors via an Ethernet communication link using LabVIEW’s built-in data socket transfer protocol. Fault Tolerant Control: Siam Photon Source The Orbit Control Graphical User Interface (GUI)

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 12 Commissioning Results Without OC The 1 st phase:

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) The 1 st phase: 13 Commissioning Results With OC  m

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 14 Commissioning Results The 1 st phase: Beam current (mA) Correction current (A) Corrector power supply problems:  Low bit-resolution  Communication error The new corrector power supplies with the higher bit- resolution are strongly required!

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 15 Commissioning Results The 2 nd phase: new b i-polar power supply installation (July 2012) Invested: ~ 3,199, B. in 2012

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 16 Commissioning Results The 2 nd phase: During machine study: August 2012 (10-11hrs without “OC”)

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 17 Commissioning Results The 2 nd phase: During machine study: August 2012 (10-11hrs with “OC”)

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 18 Commissioning Results The 2 nd phase implementation: During machine study: August 2012 (10-11hrs with “OC”)

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 19 Commissioning Results The 2 nd phase: During machine study: August 2012 (10-11hrs ) (10-11hrs without “OC”) (10-11hrs with “OC”)

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 20 Commissioning Results The 2 nd phase: During machine study: August 2012 (Air temperature control) 24 FCUs: “OFF” AHU-5: “OFF”

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 21 Commissioning Results The 2 nd phase implementation: During machine study: August 2012 (Air temperature control) without “OC” with “OC”

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 22 Commissioning Results The 2 nd phase: During machine study: August 2012 (Undulator gap control)

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 23 Commissioning Results The 2 nd phase implementation: During machine study: August 2012 (Undulator gap control) without “OC” dX with “OC” +feed-forward compensation dX with “OC” +feed-forward compensation dY without “OC” dY

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 24 Commissioning Results The 3 rd phase: (BL/User implementation) The schedule will be launched as soon as possible (i.e. as soon as time is enabled)!

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) 25 Acknowledgement I would like to thank many colleagues in the machine and support group for their engagement and effort given to this project. Last but not least, I would also like to thank our admin staffs for the procurement works: Beam dynamic groupAcc. Control SUMO team

สถาบันวิจัยแสงซินโครตรอน (องค์การมหาชน) Synchrotron Light Research Institute (Public Organization) Thank you for your attention!