In this study, we design a novel air-hockey robot system that switches strategies according to the playing styles of its opponent. The system consists of a four-axis robot arm and two high-speed vision sensors. We control the robot using visual information received at a rate of 500Hz. The control system consists of three layers: motion control, short-term strategy, and long-term strategy. In the motion control layer, the robot is controlled by visual information of the puck. In the short-term strategy layer, motion of the robot is changed according to the motion characteristics of the puck. In the long-term strategy layer, the motion of the robot is changed according to the playing style of the opponent. By integrating the three control layers, the robot exhibits human-like reactions, which increase the appeal of the game. Experimental results verify the effectiveness of our proposed method.

In this paper we try to develop a host-based system and study actual sea trials via rudder based roll control method. To authors' best knowledge, the boat we investigated is the smallest among those reported in the literature. An autonomous boat model is obtained by a system identification approach. The identified system is designed with frequency-shaped sliding mode control. The control scheme is composed of a sliding mode observer and a sliding mode controller. The stability and reachability of the switching function are proved by Lyapunov theory. Computer simulations and experiment show that successful course keeping and roll reduction results are achieved.

In this paper, we describe a miniature flight platform weighing less than 700 grams and capable of way-point navigation, trajectory tracking, precise hovering and automatic takeoff and landing. In an effort to make advanced autonomous behaviors available to mini and micro rotorcraft, a lightweight/portable and inexpensive Guidance, Navigation, and Control system (GN&C) was developed. To compensate for the weaknesses of the low-cost equipment, we put our efforts in obtaining a reliable model-based nonlinear controller. The GN&C system was implemented on a small four rotor helicopter which has undergone an extensive program of flight tests, resulting in various flight behaviors under autonomous control from takeoff to landing. Flight test results that demonstrate the operation of the GN&C algorithms on a real MAV are presented.

This paper describes an object tracking system using an autonomous micro air vehicle (MAV) and demonstrate its potential use for civilian purposes. The vision-based control system relies on a color and feature based vision algorithm for target detection and tracking, Kalman filters for relative pose estimation, and a nonlinear controller for MAV stabilization and guidance. The vision algorithm relies on information from a single onboard camera. An arbitrary target can be selected in real-time from the ground control station, thereby outperforming template and learning-based approaches. Experimental results obtained from outdoor flight tests, showed that the vision-control system enabled the MAV to track and hover above the target as long as the battery is available.

Many applications of unmanned aerial vehicles (UAVs) require the capability to navigate to some goal and to perform precise and safe landing. In this paper, we present a visual navigation system as an alternative pose estimation method for environments and situations in which GPS is unavailable. The developed visual odometer is an incremental procedure that estimates the vehicle's ego-motion by extracting and tracking visual features, using an onboard camera. For more robustness and accuracy, the visual estimates are fused with measurements from an Inertial Measurement Unit (IMU) and a Pressure Sensor Altimeter (PSA) in order to provide accurate estimates of the vehicle's height, velocity and position relative to a given location. These estimates are then exploited by a nonlinear hierarchical controller for achieving various navigation tasks such as take-off, landing, hovering, target tracking, etc. In addition to the odometer description, the paper presents validation results from autonomous flights using a small quadrotor UAV.

This paper gives a novel pick-and-place hand mechanism without any actuators and sensors. Any payload does not effect to the internal mechanism at all. First we discuss the design guideline and a working principle. Second, we realize and apply the mechanism by combining a mechanical finite four states system and our previously developed passive closure gripper. Third, we analyze and clarify some properties of the hand. Furthermore, we confirm the validity of the developed hand by manipulation experiments.

This investigation presents development of a robust adaptive fuzzy controller for the locomotion control of a hydraulically actuated leg mechanism of a six-legged walking robot COMET-III. The hydraulic servo system of the robot is characterised by dead zone and other nonlinearities as well as uncertainties due to parameter variation. Therefore, adaptive fuzzy control system is a good choice for such problem. However, due to approximation errors caused by the fuzzy system we need to ensure the robustness of the adaptive fuzzy controller by some mechanism. The adaptation law is designed based on Lyapunov synthesis approach. The dead zone is compensated by a fuzzy rule based one-step-ahead controller. The experimental results exhibit a very stable locomotion system of the walking robot with tracking error in the small neighbourhood of zero

This paper presents autonomous control for micro-flying robot (muFR) and small helicopter X.R.B. In case of natural disaster like earthquake, a MAV is very effective for surveying the site and environment in dangerous area or narrow space, where human cannot access safely. In addition, it is a help to prevent secondary disaster. This paper is concerned with autonomous hovering control, guidance control of muFR, and automatic takeoff and landing control of X.R.B

This paper presents the development of vision based autonomous helicopter at Chiba University. The platform is designed to enable autonomous flight of a small-scale helicopter in unstructured environment. 3D vision system is chosen for the perception and measurement purpose. The whole system is designed with the consideration of payload, hardware availability, and software performance. The hardware is built with COTS (commercially off the shelf) products. The core control software is built on RTLinux for its real time performance. Based on the developed platform, we have studied the application of vision system for landing control. The experimental results are shown in the paper

This paper describes autonomous hovering control and horizontal guidance control with H/sub /spl infin// controller and performance verification with flight experimental results for the hobby-class small-scale unmanned helicopter. A simple black-box system identification method was applied, and single-input/single-output (SISO) non-cross coupling stable models were obtained. Cross-validation results showed close agreement in the respective output signals obtained by simulation and by experiment. Attitude control was designed as a minor feedback loop of proportional-integral (PI) blocks with a feed-forward compensator for improvement of reference-following performance. An H/sub /spl infin// horizontal velocity control system was constructed as an outer feedback loop of an attitude control. The H/sub /spl infin// controllers were designed in the frequency domain using four closed-loop control specifications and were repeatedly tuned according to the time domain specifications. Position control was constructed by a proportional-derivative (PD) controller serving as an outer feedback loop of H/sub /spl infin// horizontal velocity control. In the flight experiments, hovering performance within a 1-m diameter circle and 15-m square point-to-point horizontal guidance control were achieved. Good consistency between experimental data and simulation data demonstrates the high accuracy of the models and the adequacy of the modeling method.

In this paper, we design a feed-forward trajectory following controller by using optimal preview control theory for a helicopter, based on a transition model and an LQI position controller derived from previous work. In order to apply optimal preview control theory to trajectory following control at any given yaw angle, we propose a correction method for eliminating the disturbances due to attitude perturbations on the magnetic direction sensor. We show that there is a problem with the axis transform of position and velocity, and as a result it cannot be applied to optimal preview control at any given yaw angle. To solve this problem, we propose an alternative axis transform method. Finally, the performance of the proposed preview controller and axis transform were verified by 'circular' and 's character' trajectory following experiments.

This article is proposing a grasp recognition and grasp mapping method for a land mine clearance master-slave system. The system consists of a data glove and a powerful hydraulic hand. Because of the different structure of the master and slave hand a mapping from master grasp to slave grasp has to be implemented. The paper presents a grasp recognition method by neural network (NN) and a mapping method. The introduced mapping method allows the operator more intuitive grasping.

Our project has developed and studied high instrumentation technologies for mine detection and mine disposal using measuring equipment mounted on a six-legged teleoperated walking robots. This robot is called COMET-1 which is a full-autonomous obstacle avoidance robot or a semi-autonomous obstacle avoidance robot that requires the operator's intervention. When detecting a mine, the robot will lower each leg onto the ground safely and stably without stepping on a mine. For the simulations and experiments in the present study, the authors created a simulation model by attaching an optical proximity sensor on the foot of each leg and designed a walking algorithm using compliance control. Also, they verified the efficiency by means of walking experiments.