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For robot applications in unknown or hazardous environments, such as search and rescue, it is difficult and stressful for human beings to merely simply teleoperate a mobile robot without assistance. Consequently, much research work focuses on the means to facilitate an efficient shared autonomy between human and robot in the field of robotics. In our previous work, a novel shared autonomy system has...
To provide robots for a wide range of users, there needs to be an easy and intuitive way to program them. This issue is addressed by the robot programming by demonstration paradigm, where the user demonstrates the task to the robot. While there exist a lot approaches that use multiple demonstrations for the learning procedure, single-shot robot programming by demonstration is still a niche. Also,...
Remote center of motion (RCM) mechanisms are widely used in surgical robots to mechanically constrain the position of a certain point in the operation space. Examples of well-known RCM mechanisms include parallelogram mechanisms, spherical linkages, circular guiding arcs, etc. In this paper, a reinforced circular-guided RCM mechanism is presented. In the mechanism, a closed-looped circular-guiding...
Concentric tube robot (CTR) comprises several precurved concentric tubes which can rotate and translate independently with respect to each other. Each pre-curved tube of a CTR can be controlled to rotate axially and translate along its axis, which enables the tip to bypass obstacles and finally reach the target position. The concentric tube robots enable surgeons to perform delicate procedures by...
Breast biopsy is a procedure to get tissue sample to identify breast cancer. A radiologist performs breast biopsy by inserting the biopsy needle on the trajectory path from their opinion and experience under ultrasound-image guidance. An accuracy of needle insertion is necessary to avoid accidents; therefore, high skill and experience of radiologist are needed. Breast biopsy navigation system, with...
Real-time performance can be greatly improved, if the early recognition is implemented. In this paper, a dynamic hand gesture early recognition system is proposed. The system can recognize the gesture before it is completed. Our method is based on the Hidden Semi-Markov Models. Three-dimensional information of the gesture trajectory collected by leapmotion is the main data we used. Experiments on...
Previous research [1] has shown that, in a nonstereo viewing condition, a circular trajectory collision event (i.e. a collision between a moving object and an observer) is specified by expansion of an object and a constant rate-of-bearing (angular direction or position in the flow field) change. In the present study, we examined the optical information for detecting an imminent collision event in...
Dual-arm Underwater Vehicle-Manipulator Systems are able perform a variety of interventions tasks, and there are still many challenges related to making such vehicles autonomous. This paper presents a guidance method for generating reference trajectories for such a system by considering the main manipulator and the vehicle base as a leader unit and the secondary manipulator as a follower unit. The...
A robot accepted by animals as conspecific is a very powerful tool in behavioral biology, particularly in studies of gregarious animals. In this paper we present the first results of acceptance of a robotic fish designed for experiments on collective animal behavior. The robot consists of two modules: a fish lure fixed on a magnetic base and a miniature mobile robot guiding the lure from below the...
In this paper, a Genetic Algorithm is used to solve for the optimization problem of a quadruped rover, which is developed based on a two-dimensional model of a domestic cat. The rover's gait, pose and control parameters are optimized for two separate objectives. First, the energy consumption through applied joint torque is minimized for fixed thrust speeds. Secondly, the rover's thrust speed is maximized...
Legged locomotion is an open problem in robotics, particularly for non-level surfaces. With decreasing robot size, different issues for climbing mechanisms and their attachment and detachment appear due to the physics of scaling. This paper describes micro-scale phenomena for different adhesion methods that can be employed in microrobots. These adhesion methods are applied to a sub-2 gram legged robot,...
This paper presents a lower limb rehabilitation robot based on free gait and virtual reality, which is intended to improve therapeutic efficacy. With the help of the robot, patients with motor disabilities can walk with free gait in a virtual environment and choose between passive and active training modes. So the impaired limbs can get appropriate exercise in all clinical stages and the motivation...
This paper presents a novel approach to path planning for the formation of a swarm of autonomous robots to track a moving target in an unknown environment. This approach is based on the traditional potential fields combined with the rotational vector field. The potential field is used to repel the robots away from obstacles while the rotational vector field is added to drive robots to avoid obstacles...
In this paper, we analyze a formation control problem of two disk-shaped holonomic mobile robots without collision each other. We show that the tracking control problem can be reduced to sample stabilization of the origin of the nonlinear system defined on noncontractible manifold by exact linearization via coordinate transformation. We propose a tracking control method which is applying the Rifford-Sontag...
To improve the efficiency of multi legged climbing robot, a dynamic climbing gait is proposed for a gecko inspired mechanism with a pendular waist and linear legs (GPL). Then, a mathematical model is built and the kinetics of the climbing gait is illustrated. Trajectory of the waist, identical to centroid of the GPL model, is also discussed in this paper. The forces at the feet of GPL are calculated,...
In order to provide robots for a wide range of users, they must be easily programmable. This is addressed by various approaches of programming a robot by demonstration, where the user guides a robot through the task. We propose an approach that adapts a once demonstrated trajectory to a new situation. The system extracts the relevant reference frames using a weighting function. Then, the demonstrated...
This paper is to present a SCARA welding robot system with novel online welding teach function named handheld welding teaching (HWT), the mechanical structure of the SCARA robot has been adapted, include using two-layer reduction in the robot joints, adding magnet-clutch between the motor shaft and gear in each joint, equipping gravity balance device. With the adaptations the operator can move the...
For many tasks such as welding and polishing on complex surfaces with manipulators, teaching-and-playback is difficult and inefficient. Motion planning with offline programming is an effective and efficient alternative control mode for these tasks. In this paper, we present a method to plan motion by offline programming for tasks on spherical workpieces and develop a corresponding planning module...
A sub-optimal guidance and nonlinear control scheme based on Optic Flow (OF) cues ensuring soft lunar landing using two minimalistic bio-inspired visual motion sensors is presented here. Unlike most previous approaches, which rely on state estimation techniques and multiple sensor fusion methods, the guidance and control strategy presented here is based on the sole knowledge of a minimum sensor suite...
This paper presents a modified gait generation method based on height compensation of center of mass (HCCOM) for biped humanoid robots. The method combines natural gait plan (NGP) and 3-D linear inverted pendulum model (3D-LIPM). By analyzing the human natural gait, the HCCOM considers the effect of swinging leg for COM height, so the hip height is no longer fixed and re-planned as a periodic movement...
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