Internal Process Controls - Control of Color Imaging Systems: Analysis and Design - page 551

9.8 Obtain an inversion using control-based inversion for Problem 9.7. Use iden-

tity as the reference TRC. Process magenta separated image through the
inverted TRC and printer model.

9.9 Consider a scenario where the level 1 loop of Example 9.1 is closed for
every print and the level 2 loop of Example 9.6 is closed for every 5 prints.
Let level 1 loop be designed for a dead beat response (i.e., closed-loop
eigenvalues ¼ 0) and level 2 loop has the following closed-loop poles:

a. p 1 ¼ 0, p 2 ¼ 0, p 3 ¼ 0

b. p 1 ¼ 0.5

Give a step change in DMA targets. Sketch the expected convergence plots for
case a and b for state variables {V h ,V l , D h , D m , D l } at every print for a total of
30 prints.

0.5, p 2 ¼ 0.5, p 3 ¼

9.10 Design the gain matrix for the PI controller of Example 9.10 using the LQR
method. Compare your TC performance with the pole-placement technique.
Comment on the results.
9.11 For TC system with PI controller

a reasonable limit,
simulate the situation with integrator windup. Design a antiwindup compen-
sator with high gain L and simulate the integrator recovery and the TC
performance with antiwindup compensator.

u min ¼ 0andu max ¼

9.12 Simulate the TC performance for a system with the state feedback controller

and estimator in Example 9.10 when the TC system has a fixed transport lag of

3 and 10 cycles. Apply the Smith predictor and a PI controller and simulate the
performance again. Comment on the results.

9.13 Describe the relationship between TC control and a typical inventory manage-
ment system. Compare the controllers.

9.14 For a four-input three-output controller with TC target as one of the actuator,
design the LQR to emphasize the TC target. Show the equation for the steady-
state value and plot it as a function of weights used in TC target, with all other
weights unchanged.

REFERENCES
1. L.K. Mestha, Control advances in production printing and publishing systems, NIP20:
Proceedings of IS&T ' s International Congress on Digital Printing Technologies,
pp. 578 - 585, Salt Lake City, UT, Oct. 31 - Nov. 5, 2004.
2. T.E. Thieret, T.A. Henderson, andM.A. Butler, Method and control system architecture for
controlling tone reproduction in printing device, US Patent 5,471,313, Nov. 28, 1995; Other
US Patents 5,087,940; 5,185,673; 5,189,441; 5,231,452; 5,255,085; 5,345,315; 5,461,462;
7,162,172.
3. L.K. Mestha, Y.R. Wang, M.A. Scheuer, and T.E. Thieret, A multilevel modular control
architecture for image reproduction, in Proceedings of the IEEE International Conference
on Control Applications, Trieste, Italy, Sep. 1 - 4, 1998.
4. P. Varaiya, Towards a layered view of control, UC Berkeley, CA 94720.
5. L.K. Mestha and P. Padmanabhan, Electrostatic control with compensation for coupling
effects, US Patent 5,754,918, May 19, 1998.