- Program at a glance
  - Plenary Talks
  - Invited Talks
  - Special Session
  - Workshop & Tutorial
  - Session Time Table
  - List of Digest
- Robot World 2007

• Plenary Talk I
An Information Fusion Approach to Missile Guidance
• Name
Yaakov Oshman
• Affiliation Technion - Israel Institute of Technology
• Abstract We address the problem of guiding a missile towards an evading agile target in the presence of noisy measurements. State-of-the-art interception missiles derive their superior performance mainly from highly advanced aerodynamic configuration design, agile seekers and highly efficient fragmentation warheads, but use only relatively basic information on the state of the target. Recent advances in onboard computing and imaging technologies render the expansion of this information base feasible, thus enabling the use of advanced guidance laws.

We focus on an integrated, information fusion approach to missile guidance, which facilitates synergy between the target estimation and guidance functions of the missile autopilot. As a first example, we examine the advantages of fusing classical line-of-sight observations with target orientation (attitude) observations, obtained by implementing computer vision techniques on visual measurements acquired by high-resolution imaging sensors. We show that, by properly exploiting the various sources of information, and using the target's bank-to-turn mathematical model, the missile's closed-loop interception performance can be vastly improved even when using an off-the-shelf differential game-based guidance law, which is derived based on an unrealistic perfect information assumption.

Next we make a bolder step in the direction of estimation/guidance fusion. Existing missile guidance law design methods traditionally assume the validity of the celebrated separation theorem. This assumption permits a separate design of the optimal estimation and guidance (control) functions, while retaining the optimality of the entire guidance system. Alas, although this approach is feasible and leads to many practical and working designs, the obvious problem with it is that the separation theorem has never been proven valid in realistic (nonlinear, non-Gaussian) interception scenarios. In such cases, only a generalized separation theorem may be applied, implying a separately designed estimator, but a guidance law that takes into account the conditional probability density function generated by this estimator. Although the generalized separation theorem has been known since Witsenhausen's 1971 groundbreaking article on separation of estimation and control for discrete time systems, little has been done, so far, in this direction.

In this talk we present a new approach to fusion of estimation and guidance, under the guidelines of the generalized separation principle. To this end, the conventional notion of reachability sets is extended, introducing the notions of pursuer and evader miss-sets. Adopting a geometry-based approach the necessary conditions for guaranteeing a hit are derived in the general case of nonlinear dynamic models without constraining the analysis to the standard Gaussian noise assumptions. A nonlinear, non-Gaussian numerical study is presented, that demonstrates the performance of the proposed methodology in a 3-D realistic engagement scenario with partial information. Particle filtering is used to approximate the entire state conditional probability density function using the exact nonlinear dynamic models without resorting to the standard Gaussian noise assumptions.
• Plenary Talk II Receding Horizon Schemes for Controls, Estimations, and Optimizations
• Name
Wook Hyun Kwon
• Affiliation Seoul National University - President of IFAC
• Abstract Major achievements of receding horizon concepts applied to control, estimation, and optimization problems for state space models, hybrid models, and Markov decision processes will be surveyed. Mathematical description of these problems will be presented in a general framework of minimization and mini-maximization optimizations.

For control problems, we first introduce the receding horizon controls (RHC) for state space models with their advantages and properties. The receding horizon controls are obtained from LQ and criteria as in infinite horizon controls. As an important property of the RHC, the cost monotonicity condition is discussed for nonlinear systems. For the partial information on the state, LQ and finite impulse response (FIR) filters and output feedback receding horizon controls (OFRHC) are introduced for linear systems. Specially, we introduce the separation property that the overall systems are composed of the state feedback RHCs and the FIR filters. Popular generalized predictive controls (GPC) for I/O models are also introduced as output feedback controls and compared with the LQ OFRHC for state space models. It is shown that RHCs for unconstrained systems can be easily extended to constrained systems due to the receding horizon scheme. Useful invariant sets for handling the input and state constraints will be covered and how to represent a form of linear matrix inequalities (LMIs) will be dealt for numerical programming.

For state estimation problems, receding horizon filters for piecewise-affine hybrid systems are introduced. The stability condition with respect to the horizon size and the weighting on the estimated state at the initial time of the receding horizon will be discussed with a connection to cost monotonicity. Algorithms for the computation will be discussed.

For optimization problems, a receding horizon approach is introduced for Markov decision process. Best policies for one person average rewards and two person zero sum games will be reviewed and their properties are shortly discussed. Above two criteria for Markov decision process will be compared with LQ and ones for state space models in view of minimization and mini-maximization.
• Plenary Talk III
New Actuators for Advanced Mechatronics
• Name
Toshiro Higuchi
• Affiliation The University of Tokyo
• Abstract Applications of actuators have increased in various fields. In industry, precise and high speed positioning is one of the most important technologies. In peripheral machines for computers like disc memories, small and thin actuators are necessary to satisfy the demand of reduction of thickness and weight of the products. In robotics development of powerful and light-weight actuators is a key issue to improve dynamic performance and to reduce the total weight of robots. In some cases conventional actuators seem to be difficult to satisfy these new and advanced demands. Therefore, seeking for new actuators has been activated recently. Especially, in the field of MEMS, where the dominant physical rules are different from those of the usual size, new small actuators utilizing electrostatic force, heat deformation, piezoelectric materials, shape memory, and so on have been proposed and developed.
In my laboratory, a number of unique actuators and drive technologies were invented and realized. Among them, first, the following two actuators using piezoelectric materials, impact drive mechanism and surface acoustic wave motor, are introduced with applications. Impact drive method can move an object with a step of several nm to micrometers for a long distance by using rapid deformation of a piezoelectric element. The surface acoustic wave motor is a very thin ultrasonic motor with promising properties like large thrust, high velocity, and quick response. Then, as applications of electrostatic force, powerful electrostatic motor and new technologies of electrostatic transportation of particles, powder and droplets, sheets and films, and thin plates, are presented respectively with their principles and devices. And combining the technologies of electrostatic suspension without mechanical contact and electrostatic drives, super clean transportation devices for 300 mm and 400mm silicon wafers and thin plates of glass for flat displays are introduced.


Organized by ICROS(Institute of Control, Robotics and Systems)
Bucheon Techno Park 401-1506, 193, Yakdae-Dong, Wonmi-Gu, Bucheon-City, Gyeonggi-Do, 420-734, Korea
Phone : +82-32-234-5801/ Fax : +82-32-234-5807/ E-mail : conference@icros.org