We consider nonlinear model predictive control for an enhanced wastewater treatment plant(EWWTP) conducting the anaerobic anoxic oxic (A2O) process to improve effluent water quality.The A2O process is modeled with an activated sludge model (ASM3+Bio-P), for which nonlinear model predictive control is applied. After formulating the cost function, we conduct numerical simulation and compare the proposed method with the conventional method, which consists of PI control and feed-forward control. Finally, it is shown that the performance of the proposed method is superior to that of the conventional method. It is also shown that real time optimization for the nonlinear model is achieved.
An electric wheelchair for indoor use should automatically avoid obstacles in its path and stop at hallway intersections to await instructions from the user. Here we propose a path control method in which an environment map including indoor hallway intersection information is constructed and self-position is estimated in combination with a particle filter. In this way, an electric wheelchair is semi-autonomously controlled. Using data from a laser range finder, the center of an intersection is estimated from the collected intersection information by using our intersection recognition technique. Through use of the intersection map and intersection recognition technique, the initial position from the particle filter can be estimated; this has the benefit of using the intersection itself as the target. Also, there is no need to change the environment in advance by positioning artificial landmarks, thus allowing cumulative error to be removed. This proposed method is applied to a modified electric wheelchair and the effectiveness is examined experimentally.
In this paper, we deal with two problems of static output feedback for input-affine polynomial dynamical systems. One is to design a static output-feedback controller so as to render a prescribed algebraic set invariant for the resulting closed-loop system. The other is to design a static output-feedback controller so as to realize a prescribed vector field on a prescribed algebraic set. It is shown that the two problems can be represented by a particular inclusion of polynomials, and the inclusion can be solved. As a result, all the static output-feedback controllers required in the problems can be exactly represented by using free polynomial parameters.
This paper proposes an error estimation of a numerical method for solving Hamilton-Jacobi equations of nonlinear optimal control problems, called stable manifold method. Then, a rapid numerical algorithm is derived from the estimation. In the algorithm, the convergent sequence with respect to solutions on stable manifolds that are equivalent to the pair of optimal feedback gains and trajectories is improved. The new algorithm has three advantages, rapid calculation, extended radius of convergence and low memory consumption.