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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)...
To prevent the human injury or breakage of the robot caused by interaction or collision with the robot and its environment, it is an important issue to introduce robot softness. However, because not only softness but also stiffness is required for precise task execution, the simultaneous realization of softness and stiffness using time varying stiffness is required in the real environment. We focus...
Reinforcement learning in the high-dimensional, continuous spaces typical in robotics, remains a challenging problem. To overcome this challenge, a popular approach has been to use demonstrations to find an appropriate initialisation of the policy in an attempt to reduce the number of iterations needed to find a solution. Here, we present an alternative way to incorporate prior knowledge from demonstrations...
This paper presents a method for mapping captured human motion with stepping to a humanoid model, considering the current state and the controller behavior. The mapping algorithm modifies the joint angle, trunk and center of mass (COM) trajectories so that the motion can be tracked and desired contact states can be achieved. The mapping is performed in two steps. The first step modifies the joint...
Pectoral foil structure and motion discipline of cow-nosed ray as nature prototype is analyzed. A bionic pectoral fin is designed according to the analysis results. Propulsion performance of the bionic fin at sinusoidal motion law is studied experimentally on a towing platform, at the oscillating frequency from 0.2 Hz to 2 Hz and amplitude from 2.5° to 30°. Well driving ability is obtained, and maximal...
Most of the literature reactive control laws have much difficulties to handle properly constraints such as joint limits, obstacles and saturations, including them as equalities in the Inverse Velocity Kinematics (IVK) problem. Actually, it seems relevant to handle them through inequalities, as the constraints are more numerous than the number of DOFs. However, the intuitive constraints expression...
The high power ability of humanoid is desired for application of nursing or running or jumping motions. Achievement of the actuator of light and powerful equivalent to humans is required. In this paper, we propose a method to extract inherent performance from motors by an active temperature control. The method safely improves the output of motors. The active temperature control is achieved by combining...
This paper presents a methodology based on a variation of the Rapidly-exploring Random Trees (RRTs) that generates feasible trajectories for autonomous vehicles with holonomic constraints in environments with obstacles. Our approach is based on seventh order Bézier curves to connect vertexes of the tree, generating paths that do not violate the main kinematic constraints of the vehicle. The methodology...
Middle ear surgery requires micro-surgical techniques and may benefit from robotic assistance. A prototype of tele-operated system is presented. Methods to determine design specifications, kinematic structure and optimization of the micro-manipulator are described. First evaluation of the robot by a stapedial removal through the external auditory meatus in human temporal bone specimens, simulating...
Online optimal planning of robotic arm movement is addressed. Optimality is inspired by computational models, where a “cost function” is used to describe limb motions according to different criteria. A method is proposed to implement optimal planning in Cartesian space, minimizing some cost function, by means of numerical approximation to a generalized nonlinear model predictive control problem. The...
This paper proposes a new 4-Degree-of-Freedom (DOF) master-slave system for 3 dimensional needle steering. Both master and slave devices are commonly composed of a 3 DOF spherical type parallel mechanism and a 1 DOF needle insertion mechanism. This system provides users with 3 dimensional needle steering and force reflection capabilities. The real time forward solution of the master device is addressed...
This paper describes the design and development of a new actuator with adjustable stiffness (AwAS) which can be used in robots which are necessary to work close to or physically interact with humans, e.g. humanoids and exoskeletons. The actuator presented in this work can independently control equilibrium position and stiffness by two motors. The first motor controls the equilibrium position while...
This paper describes a control strategy for throwing motion of the springed Pendubot based on the concept of unstable zero dynamics. An underactuated two-link planar robot called the Pendubot is investigated to realize dexterous actions of the superior limb in human throwing motion. A torsion spring is mounted on the passive joint of the Pendubot representing the flexibility of the cubital joint....
In this paper, "New form of the Euler-Bernoulli equation" has been defined and it has been directly derived from "Source form of the Euler-Bernoulli equation". The complete analogy between the original solution of the Euler-Bernoulli equation and the solution of direct kinematics in robotics (transformation matrix) has been defined. The analogue between the "Source form of...
Extended Kalman Filter (EKF) has been a popular approach in localization of a mobile robot. However, the performance of the EKF and the quality of the estimation depends on the correct a priori knowledge of process and measurement noise covariance matrices (Qk and RK, respectively). Imprecise knowledge of these statistics can cause significant degradation in performance. In this paper, the Adaptive...
We show that inverse kinematics of different tools can be efficiently learned with a single recurrent neural network. Our model exploits all upper body degrees of freedom of the Honda's humanoid robot research platform. Both hands are controlled at the same time with parametrized tool geometry. We show that generalization both in space as well as across tools is possible from very few training data...
This study examines how human movements are adapted when interacting with another person. It is also considered that the sequence of the movement can be to the choice of both actors. Different parameters of pick-and-place movements are compared in situations in which one person is moving alone or conjointly with a partner while the sequence of the task was predefined or made up by the participant...
In this paper, we propose an evolutionary approach to develop an attentive executive control system for a robotic agent. We consider a behavior-based system endowed with simple attentional mechanisms that regulate sensors sampling rates and action activations. In this context, the overall emergent attentive behavior is specified by a finite set of parameters regulating a process of adaptation w.r...
In this paper, the Mobile Parallel Robot (MPR) with structural configurations of PPUU (Prismatic - Prismatic - Universal - Universal) is developed. The inverse kinematics is firstly derived and a specific control system is presented. The control system integrates the features of parallel robot and mobile robot. Five control modules are included in the control software. By using the omnidirectional...
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