非线性系统开闭环PD型迭代学习控制及其在机器人中的应用

针对一类非线性时变系统的迭代学习控制问题提出了一种开闭环PD型迭代学习控制律 .这种迭代律同时利用系统当前的跟踪误差和前次迭代控制的跟踪误差修正控制作用 ,即在开环迭代学习控制的基础上引入一反馈环形成反馈 前馈迭代学习控制律 ,提高系统的跟踪性能 .文中给出了使此迭代学习算法收敛的充分条件和必要条件 .最后 。

低位直肠癌保肛手术的研究进展

世界范围内结直肠癌发病率呈逐年上升趋势,仅次于肺癌、胃癌位居第三,严重威胁人类健康。自1908年以来,Miles推出的经腹经会阴联合直肠癌根治术（Miles术）是直肠癌根治术的金标准。但Miles术创面过大,尤其不保留肛门行结肠造瘘术,严重影响患者术后的生活质量。随着治疗模式的改变,手术已从单一的追求根治转向在保证根治前提下尽量提高生活质量。随着保肛观念的不断更新及微创等新技术、新理论的出现,低位直肠癌保肛率有了显著提高。本文就低位直肠癌保肛手术的研究进展做一综述。

美国国家科学基金会资助大学新建六所工程科学研究中心

美国总统科学顾问乔治·基沃思在1985年的一次讲话中分析美国大学的现状时指出:“八年前,美国的大学在促进科学知识方面取得了显著成绩,但其结构并不完全适应目前工业发展所带来的各种挑战,研究工作仅限于高度专业化的专业课题”,“为此,准备建立一些大学生、工业部门的科学家及工程师们得以共同解决现代工业不断提出来的各种技术问题的大学研究所”。这些研究中心的主要任务之一是将培养一批掌握未来工业世界所需的各种技术的学生;同时。

A new accelerating algorithm for multi-agent reinforcement learning

In multi-agent systems, joint-action must be employed to achieve cooperation because the evaluation of the behavior of an agent often depends on the other agents’ behaviors. However, joint-action reinforcement learning algorithms suffer the slow convergence rate because of the enormous learning space produced by joint-action. In this article, a prediction-based reinforcement learning algorithm is presented for multi-agent cooperation tasks, which demands all agents to learn predicting the probabilities of actions that other agents may execute. A multi-robot cooperation experiment is run to test the efficacy of the new algorithm, and the experiment results show that the new algorithm can achieve the cooperation policy much faster than the primitive reinforcement learning algorithm.

Mechanism Design of Palletizing Robot Based on Translating Cam Principle

Palletizing robot technology has been applied more and more extensively in logistics automation field.But there are some limitations in the current single-arm palletizing robot that it cannot do effective work in the process of moving back to the taking-end and the mechanical arm has so many freedoms that its control system is relatively complex.Based on the translating cam principle,a novel palletizing robot is designed.The horizontal movement of the palletizing mechanical arm is controlled by changeable outer slides,and the vertical movement is controlled by partitioned up-and-down spindles.To improve palletizing efficiency,the single palletizing mechanical arm is changed into multi-arm.Moreover,to improve its kinematic properties,the acceleration operating performance,joint driving force and palletizing trajectory are optimized through the multi-objective delaminating sequence method.According to the optimization results,the 3D model of the multi-arm palletizing robot is built in Pro/E,and the kinematic simulation is made.The simulation results show that the novel mechanism and optimization parameters are rational and feasible.This novel palletizing robot has the advantages of cam mechanism,so it simplifies the driving mode of palletizing movement and can lower the requirements for controlling system.At the same time,it can increase palletizing efficiency further by adding mechanical arms.

Discrete wavelet transform-based fault diagnosis for driving system of pipeline detection robot arm

A real-time wavelet multi-resolution analysis (MRA)-based fault detection algorithm is proposed. The first stage detailed MRA signals extracted from the original signals were used as the criteria for fault detection. By measuring sharp variations in the detailed MRA signals, faults in the motor driving system of pipeline detection robot arm could be detected. The fault type was then identified by comparison of the three-phase MRA sharp variations. The effects of the faults were examined. The simulation results show that this algorithm is effective and robust, it is promising for fault detection in a robot's joint driving system. The method is simple, rapid and it can operate in real time.

Research on Robotics Application in Fruit Harvesting

The study was aimed to identify the problems and also to suggest some solutions for robotic systems applications in harvesting of kiwi and apples. The results obtained show that physicomechanical properties of the harvested fruits had an effect on the use of robotic systems. Parameters such as weight, height, width, thickness and surface area were identified as the main effect in robotic fruit harvesting. Image processing techniques also had direct effect on robotic systems operation which therefore requires careful selection procedure to achieve results accuracy. It was observed that the C# programming language used in robotic systems fruit harvesting should be parallel with the image processing to ensure accurate conversion of kinematic calculation, system input parameters and constant values. The use of hobby-type parts of a robot in the prototype study showed reliable results. However, to ensure functionality of the robotic systems application, industrial robots and servo engines should be used. It was also observed that the use of a gripper for picking the fruits from the branch must The engines that make the system work should be strong and the be made considering the physicomechanical properties of the fruit. cutting system should also be appropriate.

Main Stages of Evolution from Mechanical Automatic Systems to Humanoid Robot

Since ancient times, man has been concerned to create an artificial structure similar to itself. This concern has remained constant attention and creative thinkers most profound since antiquity until today, it is of greatest interest. This article aims to highlight the most significant moments of the evolution from mechanical creatures mythical or real, from antiquity to the present humanoid robots. There are thus shown the most significant variants humanoid imagined or realized since Talos, described in Greek mythology, continuing with mechanical machines during late Roman Empire, the Byzantine Empire and then the Renaissance of the post-renaissance, then they are shown the main achievements of the industrialization period from the nineteenth to the early part of the twentieth century, then to the most important made in the last decades of the twentieth century and early twenty-first century. The work is important to stimulate concerns academic theorists and practice but also in the industrial practice specializing in robotics and more generally in mechatronics. It also opens the prospect of defining the concept of an artificial humanoid useful both for human prosthesis with certain disabilities, and a humanoid robot performance.