【作者】 张峰；

【导师】 叶玉堂；

【作者基本信息】 电子科技大学 ， 光学工程， 2014， 硕士

【摘要】 光电视觉机器人是机器人领域的一个重要分支,广泛应用于工业生产和制造领域,其研究水平高低可以作为衡量国家工业自动化水平的重要标准。至今,ABB、KUKA、安川等国外研究团队技术较成熟。中国国内机器人市场主要还是被国外所垄断,一些机器人应用场合大都进口国外的整套机器,国外机器人控制精度和稳定性比较高,但是成本非常高。光电视觉机器人的核心技术在于:快速精确识别物体,最优运动路径规划,实时高精度控制。目前,国内的机器人大都是基于MCU(Micro Controller Unit)的无视觉识别的系统,缺少视觉模块在很大的程度上限制了机器人的使用场合,而且现有的成熟通信接口模块如CAN(Controller Area Network)总线、串口、USB(Universal Serial Bus)等在实时性能上的限制都不能满足机器人的要求。本文中所研究的光电视觉机器人采用PC作为控制系统的上位机,负责发送运动控制指令,显示人机交互界面等。下位机采用高并行执行能力的FPGA(Field-Programmable GateArray)执行上位机指令,同时集成刷新周期小于100 us的EtherCAT实时以太网作为上、下位机的通信接口模块。该下位机模式可以很大程度上提高控制精度,在数据传输实时性和执行指令并行性得到保证的前提下,机械的位置刷新效率就更高,上位机对位置的规划也就越精确。本论文中设计并制作了FPGA核心板、EtherCAT实时通信模块、伺服驱动接口、光电传感器接口等硬件电路。同时编写下位机软件代码,主要分为两个部分,且均是在FPGA上完成。FPGA分配一部分资源用来实现控制,在Quartus II编辑器中完成verilog硬件控制代码,另外一部分资源用来构建NIOS II软核,NIOS II中实现EtherCAT实时以太网传输协议。在机器人系统中成功移植EtherCAT实时以太网,这对机器人控制有着非常重要的意义,其大幅缩短了传输和反馈周期。通过本文中设计的基于EtherCAT从站控制系统对机器人的改进,其已成功在企业的工业现场应用于物料上下搬运、器件打磨和码垛等作业中,机器人在工业干扰环境中仍然能够稳定运行。其中,主从站数据刷新周期提高到1 ms大大提高了通信实时性,使得机器人点重复精度为0.02 mm,水平联动速度最快可以达到5.6 m/s,各轴归零均能在7 s内完成,归零误差在2个脉冲数以内。更多还原

【Abstract】 Photoelectric vision robot is an important branch of robots, and widely used in industrial production and manufacturing. Its research level can be regard as the important standard for national industrial automation. So far, the robot core technology is still controlled by foreign advanced groups, such as ABB, KUKA, AnChuan etc. Domestic robot market is monopolized by foreign countries, they mostly choose to import a complete set of machine abroad, because foreign robot has higher control accuracy and stability, but the cost is very high. The core technology of photoelectric vision robot is at identifying the object quickly and accurately, planning the optimal motion path, and real-time & high precision controlling. At present, the domestic robots are mostly based on MCU(Micro Controller Unit) without visual identification system, which restrict the using of robot in a large extent. And the mature communication interface module such as CAN(Controller Area Network) bus, serial port, and USB(Universal Serial Bus) can not meet the real-time requirements of robot.PC is used as the master of the control system, and it is responsible for sending motion instructions, displaying human-computer interaction interface, etc. The slave is constructed by FPGA(Field-Programmable GateArray), which has highly parallel execution ability. It is responsible for executing master’s commands. The communication interface of master and slave is EtherCAT real-time Ethernet, which has less than 100 us refresh cycle. EtherCAT can largely improve the control accuracy depends on the real-time data transmission. The higher position refresh efficiency is, the more accurate the master can plan the position.In this thesis, several hardware circuits are designed and produced, such as FPGA core board, EtherCAT real-time communication module, interface of servo drive and photoelectric sensor, and others. At the same time, the slave software codes are mainly divided into two parts, which are both completed in FPGA. The verilog hardware control codes are edited in the Quartus II, another part is built on NIOSII soft core for EtherCAT real-time Ethernet transport protocol. Transplanting EtherCAT real-time Ethernet in the robotic system has very important significance for robot control, because it greatly shortens the transmission and feedback cycle.Our photoelectric vision robot is successfully uesd in materials handling up and down, grinding and palletizing in the industrial noise environment. The repeat accuracy of robot is 0.02 mm. Its horizontal linkage fastest speed is 5.6 m/s. And it can move back to the zero position within two pulses error.更多还原