This paper shows that the concept of algebraic controllability is equivalent to the concept of accessibility. Moreover, the paper gives a reduction condition for checking whether or not a given nonlinear mechanical control system is algebraically controllable. Through a quadrotor unmanned aerial vehicle example, it is demonstrated that the condition reduces a computational complexity for checking whether or not the system is algebraically controllable.
This paper investigates potential game theoretic cooperative control. In particular, it focuses on payoff-based learning for potential games with a potential function equal to the formulated social welfare function. One of the authors' previous works on the topic provided a conjecture that taking irrational decisions in the payoff-based learning process is essential in achieving the potential function maximization. To reinforce the conjecture, the authors refine an algorithm, called simple experimentation, and present a novel payoff-based learning algorithm with irrational decisions. Then, the maximization is rigorously proved. The effectiveness of the present algorithm is finally demonstrated through simulation.
This paper gives a new method for robust D-stability analysis of linear systems with real structured uncertainties using the stability feeler. The proposed method has an improvement over past ones presented in a couple of conference papers. Past ones can be applied only to Hurwitz stability analysis. On the other hand, the proposed method can be applied to not only Hurwitz stability analysis, but also other D-stability analysis.
Multi-legged animals exhibit versatile gait patterns in response to their locomotion speed, body properties, and the environment. Quantitative measures are needed to evaluate the gait patterns, and several have been proposed so far. However, they could provide only limited information about the gait patterns, or they were only applicable for the evaluation of specific gait patterns. The authors propose a simple measure for evaluating gait patterns, focusing on the phase relationship among all legs. Unlike the previous measures, the proposed measure can be used for the quantitative evaluation of any gait pattern of animals having any number of legs. The authors demonstrate the applicability of the proposed measure by using hexapedal locomotion as an example.
This paper examines the problem of exponentially-weighted H∞ adaptive filtering and shows that its suboptimal solution reduces to a recursive algorithm which is slightly different from the RLS algorithm. Based on this similarity, its fast array form is immediately obtained by following the derivation of the fast RLS array algorithm. Also a theoretical expression for its steady-state mean-square error is provided. Several numerical examples indicate that the exponentially-weighted H∞ filter can achieve a proper balance between H∞ and H2 (least squares) filtering criteria.
This paper has proposed a gap selection and path generation method during merging maneuver of automobile. In this method the merging problem of one merging vehicle and multiple main lane vehicles is formulated using a model predictive control method. Lanes of a motor way are approximated with proposed smooth lines. Assuming that the main lane vehicles run on the centerline of the main lane, an appropriate path of the merging vehicle can be simply designed and modified according to the motions of the main lane vehicles. To generate mild merging, accelerations of all the relevant vehicles are constrained. Effectiveness of the proposed method is validated by computer simulations of the merging maneuvers of one merging vehicle and two main lane vehicles in different conditions. An example of actual cooperative merging maneuver is generated by the proposed method. Further the collision avoidance ability and the initial condition dependent property of the proposed method are tested.
This paper discusses the bilateral control of flexible master-slave arms actuated by a high-geared servomotor with time-varying delays. This system consists of a rigid master arm and a flexible slave arm, which are connected by a communication network that has time-varying transmission delays. The flexible slave arm is controlled by a proportional-derivative-strain feedback controller realized by a high-geared servomotor for reducing undesirable vibration and controlling rotational position. On the other hand, a proportional-derivative controller is employed for generating reaction torque for the rigid master arm. The stability and passivity of the proposed system are proved using Lyapunov stability theory. To confirm the performance, numerical simulations and experimental studies were demonstrated.
This paper considers an output feedback control problem for discrete-valued input systems. The proposed controller achieves model following control for networked control systems and embedded devices with low-resolution AD/DA converters. The synthesis problem the authors address is the simultaneous synthesis of the nominal controller and the delta-sigma modulator (where the modulators are called the dynamic quantizers). The proposed approach is based on the invariant set analysis and the LMI technique. First, this paper considers a controller structure for model following control. Second, this paper proposes a controller analysis condition for quantized feedback systems. Third, the authors provide a simultaneous synthesis condition that is recast as a set of matrix inequalities. Finally, to verify the validity of the proposed method, numerical examples are presented and then the contributions related to the existing dynamic quantizer synthesis are clarified.