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This paper considers Nonlinear Model Predictive Control (NMPC) in the context of snake robot locomotion. NMPC is an optimal control technique that offers the ability of handling constraints although requiring relatively significant computational resources. In detail, we show how NMPC can be applied to achieve straight line path following control of snake robots. The paper presents simulation results...
This paper presents an averaged model of the velocity dynamics of an underwater snake robot, suited for stability analysis and motion planning purposes for general sinusoidal motion gait patterns. Averaging theory is applied in order to derive a model of the average velocity for a control-oriented model of an underwater snake robot that is influenced by added mass effects (reactive fluid forces) and...
This paper presents a novel method based on the velocity disturbance to control the locomotion of a snake-like robot. The inputs are joint torques which are derived from the dynamics equations. The traditional dynamics equations of a snake-like robot are complex, so a simplified dynamics equations are firstly derived based on the differential geometry theory. Then the velocity disturbance is introduced...
In neurosurgery, effects of deformation should be considered to avoid damaging brain tissues. The goal of this study is to develop an automatic path planner considering the deformation of brain tissues. This paper shows a scheme which combines FEM (Finite Element Method) and an optimization method for optimization of retraction in order to approach a deep part of a brain. Also, evaluations of two...
To improve the safety during the robot assisted orthopaedic surgery, the authors propose an algorithm to detect the break-through of twist drill bit for the bone drilling based on wavelet transform. The drilling force is recorded and real-time discrete wavelet transform is applied. The key part of the algorithm uses the search of modulus maxima along different wavelet transform scales to find the...
The catheter based minimally-invasive closure of the left atrial appendage for stroke prevention can be realized by placing foldable structures in the heart with the help of a catheter. As a platform for the development and the evaluation of new devices, a phantom was developed that allows to perform the intervention under realistic imaging conditions. The centerpiece of the phantom is an anatomical...
The middle ear is a sophisticated mechanism which transmits sound waves from the outer ear to the inner ear, while it amplifies and filters the sound waves depending on their frequency. However, the sound path can be broken due to traumas, infections, ossification or alteration. In this case, the surgeons reconstruct the sound path with an implant, mostly with passive titanium prostheses. Developers...
Nowadays robot-assisted minimally invasive surgery (MIS) is popular because of numerous benefits to patients. However, the surgical performance evaluation methods have always failed to catch up with the development speed of surgical robot system technology. In this paper, a method ‘SOE’ to evaluate surgeons' robot-assisted MIS operation skill is provided. On the basis of third-person data and first-person...
Robot localization is one of the hottest research spots. Many scholars have studied the landmark localization which is cheap, stable, and simple in the indoor environment. This paper presents a low-cost localization system based on the artificial landmarks with two degree of freedom platform camera. The landmarks are put on the ceiling in order to decrease the interference. A 2-DOF pan-tilt has been...
Obstacle avoidance is a key problem required in the mobile robot navigation technology. In this paper, we build up a 3D environment in an intelligent surveillance robot through registration of point clouds and present a method to deal with the obstacle avoidance problem. Firstly, the framework of the intelligent robot is given. Then we register the point clouds from an RGB-D Kinect by applying an...
Navigation is one of the key issues of biped robot, especially in complicated and uncertain human-living environment. There have been challenges for ensuring the stability, efficiency and security of the biped navigation system. In this paper, a framework utilizing sampling-based footstep planner is proposed for the simulation of the biped navigation. Sensor fusion method is adopted to process and...
This paper presents a novel multi-sensor-based robot localization framework inspired by human coarse-to-fine recognition mechanism to realize fast and robust localization in the process of robot navigation. This localization framework consists of two parts: coarse place recognition and accurate location estimation. The coarse place recognition is realized using an onboard camera, whereas an image...
Robot-assisted Cardiac Surgery has remarkably helped surgeons to operate on a beating heart. The robot is preferred to move simultaneously with a point of interest (POI) on the heart surface such that surgeons are enabled to operate as if the heart is stationary. Hence an output regulation technique is proposed in this paper for the surgical robot to track the heart motion without exactly knowing...
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...
Object registration between virtual model and real object in image sequences is a challenging task. With partial reconstruction of the real object from binocular images, we approach the problem in a 3D-3D way. The system we developed includes three major components: reconstruction, 3D-3D object registration and visual augmentation from object models. For reconstruction, a perspective stereo-motion...
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...
The state-of-the-art person identification and verification technologies require apparent human biological features as inputs explicitly. In many special scenarios, however, it is impossible to obtain the apparent human biological features since such features usually require intrusive human interaction directly. In this paper, we have proposed a hierarchical skeleton feature model (HSFM) for person...
The vision system of the mobile robot is a low-level function that provides the required target information of the current environment for the upper vision tasks. The real-time performance and robustness of object segmentation in cluttered environments is still a serious problem in robot visions. In this paper, a new real-time indoor scene segmentation method based on RGB-D image, is presented and...
In this paper, a simple and robust method to recover ego-motion from a RGB-D camera is proposed. For our algorithm, no assumptions about the moving object or dynamic scenes are needed. Using the optical flow fields computed from the image sequence and depth information obtained from the RGB-D camera we estimate the ego-motion parameters. Our experiments have shown that using the intensity image and...
Detecting and tracking humans are key problems for human-robot interaction. In this paper we present an algorithm for mobile robots to detect and track people reliably, even when humans go through different illumination conditions, often change in a wide variety of poses, and are frequently occluded. We have improved the performance of face and upper body detection to quickly find people in each frame...
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