Controller is the core system of industrial robot, which is equivalent to the “central nerve” of robot. Its structure and manufacturing technology have been strictly confidential. At present, what can be known is that it mainly includes five aspects: hardware structure, system structure, control software development environment, special operating system and robot servo communication bus technology.
Hardware structure of control system
The hardware structure of industrial robot control system mainly refers to the microprocessor and the chip that constitutes the microprocessor. In recent years, with the rapid development of microelectronics technology, the function of microprocessors has been enhanced, but the cost has been declining. There have even been 32-bit microprocessors for $1 to $2. The microprocessor with high cost performance makes the robot controller reach a new level.
At present, the robot controller is mainly composed of arm, DSP, powerrpc and Intel chips with strong computing power. Because the general-purpose chips can not meet the requirements in function, SoC technology is adopted in all chips, which integrates specific processors with the required interfaces. This can greatly simplify the design of peripheral circuit, reduce the size of the system and reduce the cost.
Architecture of control system
In the industrial robot controller, the division of functions and the information exchange between the functions are very important, which involves the architecture of the controller. There are two basic partition methods for open controller architecture, which are based on hardware hierarchy structure and based on function partition structure. The former has a simple structure and a wide range of applications; the latter is relatively complex because it takes software into account.
Control software development environment
Generally, industrial robot manufacturing companies have their own independent control software programming languages. Many universities have done a lot of research on the software development environment, and provided a lot of open source code, which can be integrated and controlled under part of the robot hardware structure. The existing robot system development environments at home and abroad include teambots, v.2.0e, aria, v.2.4.1, player / stage, v.184.108.40.206.6.2, pyro. V.4.6.0, Carmen. V.1.1, etc.
Special operating system for robot
The robot special operating system mainly includes VxWorks, Windows CE, embedded Linux, μ C / OS – Ⅱ and DSP / BIOS. VxWorks operating system is an embedded real-time operating system, which has a tailorable micro kernel structure. It can provide efficient task management, flexible inter task communication, microsecond interrupt processing, posix1003.1b real-time extension standard and other functions. It supports a variety of physical media and standards, complete TCP / IP network protocol, etc.
Windows CE system has good compatibility with windows series, and provides a kind of operating system platform with rich functions for dynamic applications and services of handheld devices and wireless devices, which makes Windows CE system very easy to promote.
There is no essential difference between embedded Linux system and ordinary Linux system. As its source code is open and free, users can modify it to meet their own needs as long as they understand UNIX / Linux and C language.
μ C / OS – Ⅱ is a famous real-time kernel with open source code. It is specially designed for embedded applications. It can be used in 8-bit, 16 bit and 32-bit single-chip microcomputer or digital signal processor. It has good portability, and has a preemptive kernel, which can be solidified and tailored.
DSP / BIOS is a tailorable real-time multitask operating system kernel specially designed by TI company for its tms320c6000tm, tms320c5000tm and tms320c28xtm series DSP platforms. It consists of three parts: multithreaded real-time kernel, real-time analysis tool and chip support library. It can develop programs by using real-time operating system and develop complex DSP programs conveniently and quickly.
Robot servo communication bus technology
At present, there is still a blank in the field of servo communication bus for industrial robot system in the world. In practical application, some commonly used buses, such as Ethernet, can, 1394 and USB, are usually used in the industrial robot system according to the system requirements. Most of the communication control bus can be divided into two categories, one is based on RS-485 and line driven technology, the other is based on real-time industrial Ethernet high-speed serial bus technology.