Applied Mechanics and Materials Vol. 442

Abstract: This paper focuses on a single crane scheduling problem which is motivated by cooled-rolling material warehouse in the iron and steel enterprise. As storage technological requirement, coils have been stored on the pre-specified position in two levels. If a demanded coil is in the upper level, it can be picked up directly. If a demanded coil in the lower level is blocked by un-demanded coils, the coil can not be transported until all the blocking coils are shuffled to another position. Our problem combines transportation and shuffling simultaneously for crane to pick up all demanded coils as early as possible to designated place (makespan). We first propose a mixed integer linear programming (MILP) model. Some analytical properties are further provided. Based on these properties, we propose a polynomial-time heuristic algorithm. Numerical experiments are carried out to confirm our proposed methods can provide high quality solutions.

Abstract: Workflow management systems are the powerful tools as well as the best supports for industries which involve series of complex workflows. Specifically, two of the main objectives of workflows management system are (1) ensuring the correctness and integration of workflow advancement, and (2) carrying workflow forward to the maximum extent automatically. To ensure the correctness and integration of workflow management system, in this paper, a workflow management method based on the workflow node property is proposed, and a workflow management system model is given. In addition, in the given model, an automatic advance mode is proposed to make the workflow is able to be carried on automatically.

Abstract: The goal of workflow system is to guarantee that the right activities are executed and completed within the correct and ideal time periods via automation, moreover, in order to help a company to be sufficiently competitive, the workflow system it adopts should be able to ensure activities are carried out to the maximum extent as possible and to manage several workflow instances at the same time. Hence, sufficient consideration of temporal constraints and efficiency should be taken into the design process of workflow system. This paper proposes a model of workflow control based on time axis which is able to ensure one or more workflows to advance in correct time period efficiently and precisely.

Abstract: Considering the tunnel kiln temperatures characteristics of time varying nonlinear,large inertia and uncertainty, it is hard to establish accurate mathematical model, and affect the adjustment of the control system. Frequency conversion motor adjust the size of the gas and air flow to change the temperature in the system.Conventional PID have the parameter coupling problem,the control speed is slow and the overshoot amount is big.So the paper design a fuzzy PID, combined with the certainly of PID control and the intelligece of the fuzzy control.It makes a effective self-tuning of the PID controlled parameters. Through Matlab simulation experiment, it show the fuzzy PID control can reduce the overshoot time and the overshoot amount ,enhance the stability of the system effectively.

Abstract: A clamping robot serving for several NC machines can recognize the best fit in manny blank parts. Forthermore, the shape information acquisition and pose measurment can be achieved by its computer vision system. The key question is that the clamping robot automatively choices the best fit part by statistical result of geometric dimension of all parts. The best fit part is the one that its length and its diameter are mostly proximate to the processing requirement. This choice method can save staff, reduce working allowance, and lessen finished cost. According to the shape information and position information, the robot can confirm the grab order, grab angle and finger joint distance. Firstly, the part image is smoothing by noise reduction technology, secondly, the feature points are extracted. The feature points present the information of the location of the mass center, the dip angle and diameter. Finally, the clamping robot can grab the most fit bar part by means of rotational motion, rectilinear motion, and finger open-close movement when the shape information and location information of the bar part have been confirmed.

Abstract: Design a robot system, it is the key technique to make kinematic analysis and build dynamic model based on the robot. This paper mainly provided introduction of the products dynamic model of four degree of freedoms SCARA robot which based on Kinematics analysis .The paper has certain reference value for actual application study the system with the same type.

Abstract: In order to improve the automated vegetable-harvesting level, a robot system for truss tomato harvesting and two key technologies of picking-point recognition and end-effector design were proposed. An algorithm used the segmentation feature of the color difference 2r-g-b to recognize the truss tomato fruit and the assistant mark. According to the growth characteristics of the stem of tomato truss, the approximate fitting curve of stem and the contour of assistant mark were extracted to generate the optimal picking-point for location of tomato truss. The hardware structure of an end-effector based on flexible transmission was designed, and the function of cutting and grasping could be realized simultaneously by the end-effector. Experimental results show that the success rate for harvesting truss tomato was 88.6%, and the average execution time for picking a truss tomato was 37.2s.

Abstract: Geological body is the product of the geological evolution in the time dimension and is also the record and the process of structural changes and sequence changes presenting in 3D configuration, so 3D visualization for sedimentary-facies modeling can results in a large quantity of spatial data which can be used for detailed sedimentary-facies modeling. Lishui Depression is taken for an example and the lower of Mingyuefeng Formation is the target formation for this study. Based on the analysis of sequence cycles and sedimentary environment and interpretation of 3D geological objects, the detailed 3D sedimentary-facies model for the lower Mingyuefeng Formation is built with Sequential Indicator Simulation. Then the 3D visualization of local sedimentary-facies is detailedly presented through fence models and profile models. The results prove that the methodology is competent for 3D modeling and self-adaptive visualization of large geological objects and it is a good way to solve the problem of integration and share of geological spatial data.

Abstract: The Japanese medaka (Oryzias latipes) behavior monitoring system based on computer vision is very effective in the field of monitoring the safety of drinking water. But it is very difficult to detect the fishs body accurately and rapidly. In order to get the whole data of medaka in the real-time video sequence, a new approach to detect medaka is proposed in this paper which is based on 2D auto-threshold (OTSU), frame difference and background subtraction. With this method, the pixels in the image are divided into four parts: foreground, ghosting, foreground aperture and the others, then update background base on the data of the third part. At last, the whole fishs body can be got by some postprocessor. These methods are proved to be efficient to get the clean foreground and detect the fish in the real-time fish monitoring video.

Abstract: With the large-scale construction of smart grid, smart grid terminals widely using wireless access technology to communicate to the power systems. For ensuring the communication security, pair-wise key pre-distribution scheme is widely used, however, which introduces the complexity of key management, and insufficient security problems. According to the smart grid terminals wireless communication features, proposes an intelligent grid wireless terminal online key management scheme, which is based on the t rank binary symmetric polynomial and fully homomorphic encryption algorithm. This scheme make the communication key could be established with a few parameters between the communicating parties, which reduces the complexity of key predistribution and the amount of calculation. Moreover, the whole process of the key generation is encrypted by fully homomorphic encryption algorithm, effectively enhances the security of the scheme.