In this paper, we investigate the control and the estimation of dynamic visual feedback systems with a fixed camera. Firstly the fundamental representation of the visual feedback system with four coordinate frames is established by using the homogeneous representation and adjoint transformation. Secondly we consider the observer which is reproduced from the fundamental representation of relative rigid body motion just as Luenberger observer for linear systems. Then, the relationship between the estimation error in the 3D workspace and in the image plane is established. Next, we derive the passivity of the dynamic visual feedback system by combining the passivity of both the visual feedback system and the manipulator dynamics. The stability via Lyapunov method for the full 3D dynamic visual feedback system is discussed based on the passivity. The L2-gain performance analysis for the disturbance attenuation problem is considered via the dissipative systems theory. Finally simulation results are shown to verify the stability and L2-gain performance of the dynamic visual feedback system.
In this study, in order to clarify the human advanced brain information processing mechanism on tactile cognition, we used functional MRI (fMRI) and the manufactured tactile length stimulus presentation equipment by 12 persons normal subjects identified human brain activity region to tactile length cognition without visual guidance. By the experiment result, activation regions are found in the intra-parietal sulcus (IPS), lateral occipital cortex (LOC), dorsal occipital cortex (DOC), MT/V5, Wernicke, Broca, and right dorsolateral prefrontal area. These brain activation regions showed that tactile cognition closely associated with high order vision information processing areas and language information processing areas. On the tactile length cognition, using tactile mental representation, it is accompanied also by logical intellectual judgment at the same time it makes an intuitive cognitional judgment.
This paper deals with the optimization of the airport check-in operation system, focusing on the security screening and recourse allocation. For higher security, fine inspection of check-in baggages should be carried out. Fine inspection, however, usually deteriorates the check-in efficiency. Under the constraints on the security index and the resources, which are respectively measured by the inspection failure rate and the number of check-in stuff members, we aim at minimizing the total delay time through the whole check-in process. We formulate this problem as a knapsack-type problem with two types of variables; the screening rate and the number of servers at each check-in counter. To solve the problem, a two-dimensional dynamic programming algorithm incorporating the Lagrangean relaxation technique is presented. Through numerical experiments on sample problems, the proposed approach is shown to be useful in conducting the airport operation in a secure and efficient manner.
We discuss an optimal input and output scheduling problem for automated warehouses (referred to as AS/RS) of big scale where stacker cranes which hold a few items at a time can simultaneously and automatically input and output items to and from racks, respectively. There is a lot of items to input and output in a given planning horizon and hence the set of items must be partitioned into more than one sub-group to assign stacker cranes. Each stacker crane can input items in a sub-group into designated cells in a rack and outputs items in a sub-group from cells stored in the same rack by touring the rack. Then, we consider a simultaneous optimization of partition of the items and routing for each stacker crane to minimize the mean tour time (equivalently, to maximize the mean throughput rate). We discuss the computational complexity of the problem including the size of solution space and propose an approximation algorithm based on tabu search and heuristics. We demonstrate performances of the proposed algorithm and the stacker cranes by means of numerical experiment based on practical conditions.