产品个性化时代要求装配线能灵活适应多品类产品的自动化装配需求。然而，传统的刚性装配线生产方式，适应能力差，结构和控制系统都难以改造重用。本文面向可重构柔性装配线设计了一种装配语言，使得其控制系统具有较高的灵活性。在装配时，能够针对不同产品装配工艺，基于装配语言撰写装配程序，配置该任务所需的装配环境，使用装配指令控制其具体的装配过程，以适应新的装配作业，降低企业生产线投资或控制系统改造的成本。装配语言详细内容如下：首先，进行基于装配语言的控制系统的方案设计。根据装配的可重构性需求，获得了可重构柔性装配线的概念模型，总结出该系统的设计要求，并提出了应用层、语言层、控制层、物理层四层的基于装配语言的控制系统方案，物理层和控制层统称为平台设计。然后，进行基于装配语言的控制系统的平台搭建，具体包括结构设计和控制系统设计。完成一系列的装配工具及工夹具库的设计，进行控制系统的硬件设计，设计电气控制原理图，完成底层梯形图程序的设计，为解决PLC设备与机械臂的上位机通讯控制，分别设计两者的通讯控制程序。之后，基于可重构柔性装配平台设计了一种面向可重构柔性装配的装配语言，用于不同产品的可重构装配控制。完成该语言的语法规则、指令集、解释器的设计。软件设计将柔性装配平台上机械臂、装配单元的功能进行模块化，采用简单工厂的设计模式，引入多线程技术避免阻塞，同时控制协调各类的执行，实现同步控制。软件开发出装配语言运行的集成式开发环境，集成PLC设备和机械臂的连接控制、编辑器、运行监控等功能界面。最后，把面向可重构柔性装配系统的装配语言应用到梭阀和减压阀两个产品上。编写两者装配程序，调试运行，梭阀装配耗时约4min，减压阀在装配语言控制下装配耗时19min，相较于示教器控制方案时间缩短一半，装配语言执行可靠性大于99.99%。实验验证了基于装配语言的控制系统的结构设计、控制系统方案、装配语言的表达能力等各方面的可行性。
Nowadays, the personalized products tend to be more welcomed by the customers, which required the highly flexible assembly lines. However, the traditional assembly line, which adopts assembly machines for rigid tasks, is difficult to reconfigure its mechanical structure and control system for various tasks. Thus, the paper proposes an assembly language (A-code) for our new reconfigurable flexible assembly lines (RFAL), to further improve its flexibility and efficiency. The assembly program is written for certain assembly task based on the grammar rules of A-code. And it will configure the assembly units for different tasks, and control the specific assembly process with the use of assembly instructs. The cost is reduced by avoiding building a new customized assembly line. The details of A-code are as follows:Firstly, the overall scheme of A-code system was proposed. The general design specifications were summarized by analyzing the functions of RFAL. Then we proposed the scheme of a four layers A-code system consisted of application layer, language layer, control layer and physical layer. The latter two layers were attributed to the design of platform. Secondly, we built the platform of A-code system, namely design the mechanical structure and control system. A serial of reconfigurable tools and clamps are designed and stored in the designed tool and clamp warehouse. The control system was designed to integrate all the devices, and then implemented by the electrical schematic diagram and ladder diagram program. The communication programs are designed to transmit control signal to PLCs and robots respectively.Mostly, the paper proposed an assembly language to assemble various products for the RFAL. It includes an instruction set and syntax to write an A-code file, to express a product’s assembly processes. The interpretation of each code is realized by the interpreter. The software design adopts to simple factory pattern. And the executions of assembly unit and robot are abstracted to dozens of functions in the modularized classes. The multithread programming enables the isolated execution of assembly program, and several units run simultaneously. We also develop an integrated development environment (IDE), which include certain UIs of communications, editor, monitoring and interpreter. The IDE allows human operators to program in a simple and intuitive manner.In the experiments, two assembly cases, i.e. a simple shuttle valve and a complex relief valve, were conducted to validate the A-code system. It took 4 minutes to assemble the shuttle valve by running the assembly program. The assembling of a relief valve spent 19 minutes. The assembling time was reduced by around half. The stability of executing A-code is greater than 99.99%. The result shows that A-code can stably control the complex assembly tasks and simplify the assembly programming. Besides, the feasibility of mechanical structure design, the design of control system and the expression ability of A-code are verified.
