Methods and strategies of object localization

An important property of an intelligent robot is to be able to determine the location of an object in 3-D space. A general object localization system structure is proposed, some important issues on localization discussed, and an overview given for current available object localization algorithms and systems. The algorithms reviewed are characterized by their feature extracting and matching strategies; the range finding methods; the types of locatable objects; and the mathematical formulating methods

Tele-Autonomous control involving contact

Object localization and its application in tele-autonomous systems are studied. Two object localization algorithms are presented together with the methods of extracting several important types of object features. The first algorithm is based on line-segment to line-segment matching. Line range sensors are used to extract line-segment features from an object. The extracted features are matched to corresponding model features to compute the location of the object. The inputs of the second algorithm are not limited only to the line features. Featured points (point to point matching) and featured unit direction vectors (vector to vector matching) can also be used as the inputs of the algorithm, and there is no upper limit on the number of the features inputed. The algorithm will allow the use of redundant features to find a better solution. The algorithm uses dual number quaternions to represent the position and orientation of an object and uses the least squares optimization method to find an optimal solution for the object's location. The advantage of using this representation is that the method solves for the location estimation by minimizing a single cost function associated with the sum of the orientation and position errors and thus has a better performance on the estimation, both in accuracy and speed, than that of other similar algorithms. The difficulties when the operator is controlling a remote robot to perform manipulation tasks are also discussed. The main problems facing the operator are time delays on the signal transmission and the uncertainties of the remote environment. How object localization techniques can be used together with other techniques such as predictor display and time desynchronization to help to overcome these difficulties are then discussed

Estimating 3-D location parameters using dual number quaternions

This paper describes a new algorithm for estimating the position and orientation of objects. The problem is formulated as an optimization problem using dual number quaternions. The advantage of using this representation is that the method solves for the location estimate by minimizing a single cost function associated with the sum of the orientation and position errors and thus is expected to have a better performance on the estimation, both in accuracy and in speed. Several forms of sensory information can be used by the algorithm. That is, the measured data can be a combination of measured points on an object's surfaces and measured unit direction vectors located on the object. Simulations have been carried out on a Compaq 386/20 computer and the simulation results are analyzed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29059/1/0000092.pd

Object localization and its applications in tele-autonomous systems.

Object localization and its applications in tele-autonomous systems are studied in this thesis. The thesis first gives a thorough investigation of the object localization problem and then presents two object localization algorithms together with the methods of extracting several important types of object features. The first algorithm is based on line-segment to line-segment matching. Line range sensors are used to extract line-segment features from an object, the features may be boundary edges of planar surfaces, the axes of cylindrical surfaces, conic surfaces, or other types of surfaces of revolution. The extracted features are matched to corresponding model features to compute the location of the object. The second algorithm is more general. The inputs of the algorithm are not limited only to the line features. Featured points (point-to-point matching) and featured unit direction vectors (vector-to-vector matching) can also be used as the inputs of the algorithm, and there is no upper limit on the number of the features inputed. The algorithm will allow the use of redundant features to find a better solution. The algorithm uses dual number quaternions to represent the position and orientation of an object and uses the least squares optimization method to find an optimal solution for the object's location. The advantage of using this representation is that the method solves for the location estimation by minimizing a single cost function associated with the sum of the orientation and position errors and thus has a better performance on the estimation, both in accuracy and in speed, than that of other similar algorithms. The thesis discusses the difficulties when an operator is controlling a remote robot to perform manipulation tasks. The main problems facing the operator are time-delays on the signal transmission and the uncertainties of the remote environment. How object localization techniques can be used together with other techniques such as predictor display and time desynchronization to help to overcome these difficulties are then discussed. The thesis discusses two cases where object localization can help: (1) the case where direct manual control is used to perform a tele-manipulation task; (2) the case where the remote system has certain degree of automation ability.Ph.D.Computer Information and Control EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/105622/1/9023637.pdfDescription of 9023637.pdf : Restricted to UM users only

ARTICLE NO. 0019 Curve Fitting with Bézier Cubics

In this paper, a new curve-fitting algorithm is presented. 1. An image’s outline cannot be fitted by a single cubic Bézier curve piece if it contains corners. Corners are points This algorithm can automatically fit a set of data points with at which the outline’s directions take a sharp turn, or the piecewise geometrically continuous (G1) cubic Bézier curves. The algorithm consists of two steps. During the first step, significant points are identified from the given data set and are further classified as either corners or joints. Curve fitting is outlines have discontinuous tangent values. 2. An image’s outline cannot be fitted by a single cubic Bézier curve if it contains more than two inflection points. done in the second step. A weighted least-squares technique is 3. An image’s outline is difficult to be fitted by a single used to find an optimal solution for the construction of piecewise piece of cubic Bézier curve if it has large curvature changes Bézier curves. The resulting Bézier curve segments will be along certain portion of the curve. smoothly connected at all joint points. This algorithm has been applied to many digital images with good results. © 1996 Academic Press, Inc. Therefore, in most cases, an image’s outline will be fitted by using a piecewise approximation approach. A piecewise approximation to a shape consists of a number of cubic curves pieces connected end-to-end. The location and 1

Pedaling Performance Changing of Elite Cyclists Is Mainly Determined by the Fatigue of Hamstring and Vastus Muscles during Repeated Sprint Cycling Exercise

Repeated sprint cycling is an effective training method in promoting athletic performance of cyclists, which may induce severe fatigue of lower limb muscles. However, the relationship between the fatigue of each lower limb muscles and the changing of exercise performance remains unclear. In this study, ten cyclist volunteers performed a series of 6-second sprints with 24-s recovery for five times. Power, cadence, and EMG mean frequency (MNF) of each lower limb muscle group for every 2-second epoch, as well as the grey relational grade between exercise performance and MNF of each lower limb muscle group during the whole process were calculated. It has been found that MNF of Rectus femoris (RF), Vastus (VAS), Gastrocnemius (GAS), and the hamstring muscle group (HAM) showed significant negative correlation with the increase in both sprint number and intrasprint duration time, while the grey relational grade of HAM and VAS was higher than that of other muscles. The results demonstrated that the exercise performance of both power and cadence were most closing related to the fatigue degree of HAM and VAS during repeated sprint cycling exercise

Isolation, Characterization and Evaluation of Collagen from Jellyfish Rhopilema esculentum Kishinouye for Use in Hemostatic Applications.

Hemostat has been a crucial focus since human body is unable to control massive blood loss, and collagen proves to be an effective hemostat in previous studies. In this study, collagen was isolated from the mesoglea of jellyfish Rhopilema esculentum Kishinouye and its hemostatic property was studied. The yields of acid-soluble collagen (ASC) and pepsin-soluble (PSC) were 0.12% and 0.28% respectively. The SDS-PAGE patterns indicated that the collagen extracted from jellyfish mesoglea was type I collagen. The lyophilized jellyfish collagen sponges were cross-linked with EDC and interconnected networks in the sponges were revealed by scanning electron microscope (SEM). Collagen sponges exhibited higher water absorption rates than medical gauze and EDC/NHS cross-linking method could improve the stability of the collagen sponges. Compared with medical gauze groups, the blood clotting indexes (BCIs) of collagen sponges were significantly decreased (P < 0.05) and the concentration of collagen also had an influence on the hemostatic property (P < 0.05). Collagen sponges had an improved hemostatic ability compared to the gauze control in tail amputation rat models. Hemostatic mechanism studies showed that hemocytes and platelets could adhere and aggregate on the surface of collagen sponge. All properties make jellyfish collagen sponge to be a suitable candidate used as hemostatic material and for wound healing applications

SDS polyacrylamide gel electrophoresis pattern of collagens from jellyfish mesoglea.

<p>STD: molecular weight marker; RTC: rat tail type I collagen; PSC: pepsin soluble collagen; ASC: acid soluble collagen.</p