The type of the leaf vein can be a useful parameter in automatic identification of plant species. Leaf vein extraction is the precondition of discriminating the leaf vein type. In this paper a new ...method is presented for leaf vein extraction based on mathematical morphology. Firstly, the color image of the plant leaf is transformed to gray image according to the hue and intensity information. Secondly, a combined operation of mathematical morphology is applied to the image to eliminate the color overlap between the whole leaf vein and the whole background. Thirdly, image segmentation is performed with OSTU method. Finally, the leaf vein can be got after some processing on details. Experiments have been conducted with several images and the results show the effectiveness of the method. The basic idea of the method is also applicable to other linear objects extraction.
This paper describes the dynamic modeling of linear object deformation considering geometrical constraints and contact with obstacles. Deformable linear objects such as cables and strings are widely ...used in our daily life, some industries, and medical operations. Modeling, control, and manipulation of deformable linear objects are keys to many applications. We have formulated the static deformation of a linear object using the differential geometry coordinates. In this paper, we apply differential geometry coordinates to the dynamic modeling of linear objects. First, we formulate dynamic 2D deformation of an inextensible linear object based on a differential geometry coordinate system. Second, we consider dynamic deformation of the linear object when forces/moments and geometrical constraints are imposed on the object. Third, we model contact of a linear object with a circular obstacle. It can be applied to self-contact of the linear object. Finally, we show simulation results using the proposed modeling technique
This paper describes the dynamic modeling of linear object deformation based on differential geometry coordinates. Deformable linear objects such as cables and strings are widely used in our daily ...life, electric industries, medical operations. Modeling, control, and manipulation of deformable linear objects are keys to many applications. We have proposed the differential geometry coordinates to describe the 2D/3D deformation of a linear object with the minimum number of parameters. Based on this description, we have formulated the static deformation of a linear object using the differential geometry coordinates but the dynamic deformation has not been investigated yet. In this paper, we apply differential geometry coordinates to the dynamic modeling of linear objects. First, we formulate the dynamic 2D deformation of an inextensible linear object based on a differential geometry coordinate system. Second, we show simulation results using the proposed modeling technique. Next, we apply the proposed dynamic modeling to the control of a flexible link.
A planning method for linear object manipulation, especially knotting is shown. At first, topological states of a linear object are described. Next, transitions between states are defined. Then, we ...can generate possible sequences of state transition, from which, we can choose an adequate path from the initial state to the objective state. Furthermore, a method to determine the grasping points is proposed. In the fourth, a planning method is proposed. Finally, our system based on proposed methods is demonstrated
A planning method for linear object manipulation including knotting/unknotting by one hand is proposed. Firstly, topological states of a linear object are represented as finite permutations of ...crossing points. Secondly, transitions among topological states are defined. Then, we can generate possible sequences of state transitions, that is, possible manipulation processes from the initial state to a given objective state. Thirdly, a method for determination of grasping points and their moving direction is proposed in order to realize derived manipulation processes. Furthermore, a planning method for one-handed manipulation is proposed. Knotting by one hand is possible as any manipulation processes can be realized by iteration of one-handed operations. Finally, it is demonstrated that our developed system based on the above method can generate manipulation plans for raveling out of an overhand knot.
A qualitative representation method and a rough planning method of linear object manipulation including knotting in the three-dimensional space is proposed. Firstly, states of a linear object are ...represented as finite permutations of crossing points including the crossing type of each crossing point. Secondly, state transitions among those states are defined. They correspond to operations which change the number of crossing points or permutate their sequence. Then, we can generate possible sequences of crossing state transitions, that is, possible manipulation processes when the initial state and the objective state are given. Thirdly, a method for determination of grasping points and their moving direction in order to realize derived manipulation processes is proposed. Furthermore, some criteria for evaluation of manipulation processes are introduced in order to narrow down candidates for manipulation plans. Finally, that our proposed method can be applied to the rough planning of linear object manipulation is demonstrated.
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