Kimiko Motonaka

Kinodynamic motion planning and control for an X4-Flyer using anisotropic damping forces

We present a novel method to control an X4-Flyer using kinodynamic motion planning. Kinodynamic motion planning is the planning technique of generating a control input by solving the problems of kinematic constraints and dynamic constraints simultaneously, and it is useful for simpler generation of the control input. In this paper, we extend existing kinodynamic motion planning, which uses “Harmonic potential field (HPF)” and some damping forces for the control of simple point mass, to the motion planning for an X4-Flyer, which is a complex multivariable system. Then, we use “nonlinear anisotropic damping forces (NADFs),” which is proposed by Masoud, as damping force. In the simulation, a method using NADFs is compared with that using viscous damping forces. From the simulation, it is confirmed that the kinodynamic motion planning can be realized for an X4-Flyer.

Offline gain optimization in kinodynamic motion planning based on a harmonic potential field

A method of automatically optimizing gains is described for kinodynamic motion planning related to a controlled system consisting of a point mass. Kinodynamic motion planning proposed by Masoud has some gains and it is difficult to optimize such gains manually due to its interaction. Note, however, that any method for optimizing the gains has not been mentioned yet. Therefore, a method for optimizing all gains included in the kinodynamic motion planning is proposed by using a genetic algorithm.

Motion planning of a UAV using a kinodynamic motion planning method

In this research, we extend the kinodynamic motion planning using “nonlinear anisotropic damping forces (NADFs),” which had been applied to a point mass in the previous research, to the motion planning of “unmanned arerial vehicles (UAVs)”. In the proposed system, we realize the autonomous locomotion for AUVs by combining the nonholonomic control, which is already established for the attitude control method, and kinodynamic motion planning. By applying this system, the control input for moving toward the given target point can be generated automatically, while keeping its altitude and attitude. In this paper, the system for controlling an X4-Flyer, which is composed of nonholonomic control and kinodynamic control, is explained. Moreover, it is confirmed in the simulation that the proposed system can guide the X4-Flyer by using the proposed method.

3-dimensional kinodynamic motion planning for an X4-Flyer using 2-dimensional harmonic potential fields

In this research, it is aimed at guiding an X4-Flyer, which is a VTOL type UAV, to an arbitrary target point. In the previous research, we proposed a controller for an X4-Flyer to move on the X-Y plane by using a 2-dimensional harmonic potential field (HPF), assuming that the X4-Flyer keeps its altitude constantly. In this paper, the controller guides the X4-Flyer to an arbitrary target point in a 3-dimensional space by switching some 2-dimensional HPFs appropriately. It is confirmed on the simulation that the X4-Flyer can reach the arbitrary target point in the 3-dimensional space by using the proposed method.

Path generation with Human Frequency Map for a mobile robot and its path evaluation by using human movement simulations

A robot requires any path planning to respect human movements when the robot works with the person in an environment. In this study, a path planning method that respects human movements is proposed for mobile robots working in a living environment. In this path planning, we use a “Human Frequency Map (HFM)” generated by using observed human positions in a sensor-distributed space. The robot can obtain information about path candidates to a goal, pathway width and high possibility areas of human encountering. In this paper, path planning that cares about the human encountering and the pathway width is shown to be performed by superposing the current human position on the HFM. In particular, a simulation is conducted for a case that the robot runs in a living environment with several sensors. Additionally, a path planning method based on using the HFM is compared with that based on not using the HFM to prove the availability of the HFM.

A sub-target approach to the kinodynamic motion control of a wheeled mobile robot

A mobile robot with two independently driven wheels is popular, but it is difficult to stabilize it by a continuous controller with a constant gain, due to its nonholonomic property. It is guaranteed that a nonholonomic controlled object can always be converged to an arbitrary point using a switching control method or a quasi-continuous control method based on an invariant manifold in a chained form. From this, the authors already proposed a kinodynamic controller to converge the states of such a two-wheeled mobile robot to the arbitrary target position while avoiding obstacles, by combining the control based on the invariant manifold and the harmonic potential field (HPF). On the other hand, it was confirmed in the previous research that there is a case that the robot cannot avoid the obstacle because there is no enough space to converge the current state to the target state. In this paper, we propose a method that divides the final target position into some sub-target positions and moves the robot step by step, and it is confirmed by the simulation that the robot can converge to the target position while avoiding obstacles using the proposed method.

Flight simulations of kinodynamic control using the information around a quadrotor

The autonomous control of the quadrotor has received attention. In the previous research, we proposed the kinodynamic control using a harmonic potential field (HPF), which is a method to design a control input by considering kinematic constraints and dynamic constraints simultaneously. However, it was assumed that the environment was already known and the HPF of the environment was prepared in advance. Therefore, in this paper, assume that a final target position is given to the quadrotor and the quadrotor moves by relying on the mounted sensor. It is confirmed, by a simulation using the Matlab, that the proposed method can guide the quadrotor to the target position.

Kinodynamic motion planning for a two-wheeled drive mobile robot using a Harmonic Potential Field

There are many methods for making a robot with two independent driving wheels move autonomously, but kinodynamic motion planning using HPF (Harmonic Potential Field) was seldom studied up to now. Since a nonholonomic system such as a robot with two independent driving wheels includes complicated nonlinear terms generally, it is hard to realize a stable and tractable controller design: in other words, it needs a specific control method when controlling it. However, about a dynamic control method in the motion planning, it is guaranteed that a nonholonomic controlled object can always be converged to an arbitrary point using a control method based on an invariant manifold. In this research, it is aimed at realizing kinodynamic motion planning for a robot with two independent driving wheels by combining the control based on the invariant manifold and the HPF. In this paper, how to combine the invariant manifold control and the concept of the HPF is explained in detail, and the usefulness of the proposed approach is verified through some simulations.

Analysis of adaptation rate of the FXLMS algorithm

We analyze the behaviors of active noise control using a statistical-mechanical method. The principal assumption used in the analysis is that the impulse responses of the primary path and adaptive filter are sufficiently long. In particular, in this paper we analyze the adaptation rate of the mean square error (MSE) using two measures. The first measure is the MSE initial decreasing rate. The second measure is an adaptation constant. This is defined by the negative of the maximum eigenvalue of the coefficient matrix of differential equations that describe the dynamical behaviors of the macroscopic variables. Introducing these two measures, we theoretically show that the optimal step size depends on whether we focus on the rate of decrease in the MSE at the initial stage or the MSE after sufficient adaptation time.

Implementation and basic experiments of kinodynamic motion planning for a quadrotor

In this paper, kinodynamic motion planning is described for keeping the attitude of a quadrotor and converging to an arbitrary target point, while avoiding obstacles. Kinodynamic motion planning was extended for a quadrotor in our previous research, but its behavior was confirmed only in simulations. Therefore, we implement the proposed kinodynamic motion planning to an actual quadrotor, and confirm the usability of our method through basic motion experiments.