2010 IEEE/RSJ International Conference on Intelligent Robots and Systems

This paper develops full-state parametric controllers for standing balance of humanoid robots in response to impulsive and constant pushes. We also explore a hypothesis that postural feedback gains in standing balance should change with perturbation size. From an engineering point of view this is known as gain scheduling. We use an optimization approach to see if feedback gains should scale with t... View full abstract»

This paper deals with a comparative study on using water and air as actuation means for the control of a fluidic muscle (designed for air) and assesses the performance, particularly from a dynamic and energetic point of view. A medium with higher bulk modulus such as oil/water is believed to increase pressure and force bandwidths and reduce sensitivity to load variations, as is the case with conve... View full abstract»

In this paper, a mixed controller for solving the trajectory tracking and point stabilization problems of a mobile robot is presented, applying the integration of backstepping technique and neural dynamics. By introducing a virtual target point, the whole motion process is divided into two parts. The first one is employed to realize tracking control and the other one is adopted to implement point ... View full abstract»

A cooperation approach with consideration of communication limit is proposed for multi-robot area exploration, in which all the robots select local destinations satisfying the constraints on communication range and reach their destinations at the same time to communicate and fuse their map information. Firstly, the robots compute the frontier between the explored region and the unexplored one. The... View full abstract»

We present an efficient graph-theoretic algorithm for segmenting a colored laser point cloud derived from a laser scanner and camera. Segmentation of raw sensor data is a crucial first step for many high level tasks such as object recognition, obstacle avoidance and terrain classification. Our method enables combination of color information from a wide field of view camera with a 3D LIDAR point cl... View full abstract»

The representation of probabilistic graphical model often encodes a network whose size is unboundedly large. Such networks pose particular challenges to inference algorithms, specifically making the task of robot path queries highly inefficient due to poor locality of memory references. Whereas a more predictable, resolution complete method yields a highly compact graph structure that captures muc... View full abstract»

We consider a problem of rigid body motion planning in a static 3D environment. In the past, methods based on random sampling like Probabilistic Roadmap and its variants proved to be able to efficiently solve many important instances of that problem. Performance of these methods degrades drastically in the presence of narrow passages. We propose a different approach to motion planning which combin... View full abstract»

For the control of unmanned helicopters in full flight envelope, an active model based control scheme is developed in this paper. An adaptive set-membership filter (ASMF) is used to online estimate both the model error due to flight mode change and its boundary, taking advantage of ASMF, so that the model error can be assumed unknown but bounded (UBB). The proposed approach is practical because th... View full abstract»

The control of a snake-like robot is a challenging problem because of the complex dynamics and the unknown environment. We have proposed an energy-based method, called passive creeping, to control the serpentine locomotion. This paper lays emphasis on the stability and the adaptability of the method. First, the local orbital stability of the movement is explicated based on the maximal Lyapunov exp... View full abstract»

This paper presents a control architecture for the underwater locomotion control of a biomimetic amphibious robot with multi-mobility mechanism. In view of both hydrodynamic problem and engineering approach, we develop a robotic prototype capable of multi-mode motion. A robust gait control for steady swimming using the central pattern generator (CPG) is proposed and has been successfully applied t... View full abstract»

This paper presents a motion planning approach to coordinating multiple mobile robots in moving along specified paths. The robots are required to fulfill formation requirements while meeting velocity/acceleration constraints and avoiding collisions. Coordination is achieved by planning robot velocities along the paths through a velocity optimization process. An objective function for minimizing fo... View full abstract»

This paper describes a numerical method to compute van der Waals force between complex and freely oriented objects that have rough surfaces. The force calculation is implemented using the surface formulation of the force. First, the interacting surfaces are approximated with triangular meshes. Then, the surface roughness is taken into consideration by separately adding the asperity heights to each... View full abstract»

This paper presents a trajectory planning algorithm for a robot operating in dynamic human environments. Environments such as pedestrian streets, hospital corridors, train stations or airports. We formulate the problem as planning a minimal cost trajectory through a potential field, defined from the perceived position and motion of persons in the environment. A Rapidly-exploring Random Tree (RRT) ... View full abstract»

Wheeled exploration robots are prone to slip during locomotion on deformable rough planetary terrain, which leads to loss of velocity and extra consumption of energy. Experimental results show that the power required for driving a wheel is an increasing function of its slip ratio; further, the tractive efficiency decreases rapidly after it reaches a peak value when the slip ratio is between 0.05 a... View full abstract»

This paper presents the design and fabrication process of a new piezoelectrically actuated flexure-based XYZ compliant parallel-kinematics micropositioning stage with totally decoupled properties. The proposed XYZ stage consists of three limbs which are assembled in an orthogonal manner, and it has both input and output decoupling properties. Analytical models for kinematics, statics, and dynamics... View full abstract»

Localization of rail vehicles is fundamental for any autonomous systems to perform tasks in logistics or personal transport. This contribution presents a novel onboard localization system, based on an eddy current sensor system (ECS), that is capable of a precise train localization when combined with a simple topological map. In contrary to commonly applied travel distance determination by integra... View full abstract»

This paper investigates and realizes the self-sensing capability of shape memory alloy (SMA) actuators. SMA exhibits large stroke, high energy density, and requires low driving voltage. To make SMA more applicable to small scale robotic manipulations, its motion control using accurate self-sensing is necessary. The presented technique builds a self-sensing model by measuring the SMA electrical res... View full abstract»

This paper presents an efficient kinematical solution to a multi-robot system with serial and parallel mechanisms. JL-I is a reconfigurable robot featuring active spherical joints formed by serial and parallel mechanisms endowing the robotic system with the ability of changing shapes in three dimensions. The active joint here can combine the advantages of the high rigidity of a parallel mechanism ... View full abstract»

This paper describes a novel joint mechanism with variable stiffness for a human-friendly robot. In the proposed mechanism, a set of two different hollow-shaped silicone rubber cushions (SRC_trans and SRC_stiff : Silicone Rubber Cushion for transmission and for adjusting stiffness, respectively) are sandwiched between an output link and a motor-driven di... View full abstract»

This paper is focused on the problem of accurate and reliable path tracking control of a 4-wheels car-like mobile robot moving off-road at high speed. Dynamic and extended kinematic models that take into account the effects of wheel skidding are presented. Based on the extended kinematic model, an adaptive and predictive controller for path tracking is derived. This control law is combined to a st... View full abstract»

In this paper, we propose and evaluate a video communication system that compensates for user's uncongenial attitudes by coordinating the robot's behaviors and media control of the video. The system facilitates comfortable video communications between elderly or disabled people by an assistant robot for each user that expresses (a) active listening behaviors to compensate for the listener's attitu... View full abstract»

The goal of this paper is to develop a robot control system using a microcomputer for an underwater robot with a buoyancy control system based on the spermaceti oil hypothesis. Sperm whales have a spermaceti organ in their head that is filled with spermaceti oil. It is said that sperm whales control their buoyancy by melting or coagulating spermaceti oil. In the previous papers proposed an underwa... View full abstract»