NSTD Research Projects: TRP
2007: 1st, 2nd, 3rd, 4th
TRP 31. Decoupling and Disturbance Rejection Control for Target Circulation
September 2006 - December 2007
Research Objectives & Methods
The Primary objective was to modify the existing control algorithm of the pilot targe circuit (TC-1) loop to achieve precise temperature control. Safety concerns, the alarm system, and a user-friendly design became the secondary objective.
The TC-1 system has more than a single input and output, and it exhibits a nonlinear interactive property between the heater inputs and temperature outputs. For effective temperature control in multiple locations of the TC-1 system, these nonlinear interaction terms must be eliminated (decoupled) in the control loop. Eliminating these interaction terms requires the identification of these interacting (coupling) terms. After successful elimination of the coupling terms, a closed loop control algorithm can be designed which can achieve the precise tracking of the temperature on multiple locations of the TC-1 under external temperature disturbance from an EM pump.
In addition, the electromagnetic pump, used for molten lead circulation, becomes a big heat source. This, in particular, is due to its low efficiency. The disturbance observer based control methods have been reported to compensate modeling uncertainties as well as external disturbance. The disturbance observer regards the difference between the actual output and the output of the nominal model as an equivalent disturbance applied to the nominal model. The proposed disturbance observer based control algorithm achieves a precise tracking of set temperatures despite of highly coupled thermal disturbance existing in the loop.
Finally, the alarm system and a twenty-four hour monitoring and dial-out system was designed.
- Jian Ma, Mechanical Engineering
- Joon Soo Lee, Mechanical Engineering
- Woosoon Yim, Physics
- Ning Li, Project Leader, Heavy Liquid Metal Coolant Technology and Material Development, Los Alamos National Laboratory
- Xiuju (Julia) Tan, MS, Mechanical Engineering