Lei Feng network press: The author of this article is a science and technology scissor, Si Hao science and technology consultant. With the rise of domestic robots in these two years, autonomous positioning and navigation technology as the first step in the intelligentization of robots is constantly attracting attention in the industry. In order to achieve this function, many manufacturers choose to use the robot operating system ROS (Robot Operation System), today we talk about ROS system. | What is ROS? The ROS system originated in 2007. Willow Garage, an artificial intelligence laboratory and robotics company at Stanford University, developed the prototype of ROS for its Personal Robots Program. After 2008, the further development of ROS was promoted by Willow Garage. After 2012, the ROS team was independent from Willow Garage and became the Open Source Robotics Foundation (OSRF), a non-profit organization that maintains and updates ROS and provides the robot community with support and open source tools. Willow Garage PR2 Robot Platform ROS publishes approximately one version per year. The ROS versions currently under maintenance include indigo, jade, and kinetic. Some earlier versions have now ceased maintenance. ROS relies on the Linux kernel, so whenever the Ubuntu version changes, the dependencies of different versions of ROS will change accordingly. | ROS Features and Benefits Although ROS is called a robot operating system, in fact, ROS acts as a communication middleware, which is based on the existing operating system to build a complete framework for the implementation of the robot system. ROS also provides a set of utilities and software libraries for maintaining, building, writing, and executing software code that can be used on multiple computing platforms. It is worth mentioning that ROS designers take into account the different development languages ​​used by developers, so ROS's development language is independent and supports many development languages ​​such as C++ and Python. Therefore, in addition to the official package of functions, ROS also aggregates a large number of open source feature packages that developers around the world have implemented. For example, SLAMTEC has released the ROS feature package rplidar_ros for its independently developed lidar RPLIDAR. These open source packages together with ROS constitute a powerful open source ecosystem. The ROS system architecture design is also quite unique. The ROS runtime consists of a number of loosely coupled processes. Each process ROS is called a node. All nodes can run on a single processor or can be distributed. On multiple processors. In actual use, this loosely coupled structural design allows developers to flexibly add individual functional modules based on the functions required by the robot. For example, in a mobile robot that supports the SLAM function, laser data acquisition and mileage data acquisition are implemented by two nodes, respectively, for sensing the environment; the SLAM algorithm runs in another node for processing sensor data and drawing a map; SLAM The nodes and the data acquisition nodes communicate using topics. When a new camera module is added, only a new video node needs to be added in the existing structure, so that it can communicate with the SLAM node in the topic mode, and the other two function nodes do not need any changes.        ROS built indoor map Like other open source products (Linux, GCC, etc.), ROS has excellent open source genes, loosely coupled design methods, extensible software architecture, and reuse of ideas, greatly reducing the barriers to entry in the field of robotics, freeing developers from the need to The predecessors have gone through many detours and mastered a variety of knowledge before they can begin to realize their dream of robot design. Developers can use ROS's basic framework to quickly prototype systems with selected feature packs, allowing developers to spend more time developing and improving core algorithms. The user can also select certain function packages individually and integrate them into existing products to achieve specific functions. | Defects and Deficiency of ROS For robot manufacturers, the use of ROS for development, more hope to use the system to achieve the robot navigation, positioning and path planning, which depends on the SLAM algorithm (simultaneous localization and mapping, instant positioning and mapping). But as an open source project, ROS also has some problems. For example, because ROS distributes functions among various nodes, the nodes communicate based on the message mechanism, and the communication part consumes a lot of system resources. Especially when all nodes are located in the same processor, ROS still performs corresponding message distribution. Data transfer between nodes is copied through memory. A lot of system resources are wasted on communication, making the system must use high-performance processors and Storage system to make up for the loss. In other words, the use of ROS to implement SLAM requires the provision of hardware devices with superior performance. For some small-scale embedded platforms, especially for actual robot products, the consumption of computing resources and storage space will increase the cost substantially. In addition to the limitations of ROS' own system design, the use of ROS to implement SLAM requires in-depth adjustment and optimization, which requires a lot of manpower and time costs. More importantly, specific robotic products, such as floor sweeping robots, also require unique edging sweeps, sweepback sweeps, multi-room autonomous navigation, and other functions. Currently, existing ROS systems can only achieve simple construction and cannot be built. Satisfy the actual needs of sweeping robots. | Addition to ROS, but also how to do? On the road to commercial application development of robots, many technical teams and companies develop corresponding commercial products for specific functions of robots. Especially in the field of mobile robots, such as Slamware's Slamware control module, SLAM algorithm, navigation, positioning and other functions will be implemented. Integrated in a small module, and provides a multi-platform SDK for users. For specific applications such as sweeping robots, Sihan Technology also provides complete solutions, integrating its unique features such as edging cleaning, reciprocating sweeping, area division, breakpoint sweep, automatic backfill, etc., to facilitate sweeping robot manufacturers Integration does not require secondary development. Of course, compared to using open source ROS systems, selecting existing mature solutions will undoubtedly increase the cost of robot manufacturers, but considering that manufacturers must invest a lot of manpower and time for algorithm optimization and adjustment, this is also a better one. s Choice. In summary, ROS provides a standardized framework for the research and development of robots. Its convenient code reuse and effective communication among researchers can speed up the prototype design and algorithm development verification of robot products. However, to do truly stable and reliable products and select existing mature solutions can significantly reduce research and development costs, quickly obtain product prototypes, and put them into the market. Lei Feng Net Note: This article was originally included in WeChat public number. This article was published by the author of Lei Feng Network (search "Lei Feng Net" public concern) , reproduced please contact the authorize and retain the source and author, not to delete the content.
AC Contactor switch mainly used for making or breaking circuit at a long distance, suitable for controlling starting\stopping\reversing of AC motor. AC Contactor of korlen conforms to the requirement of IEC60947-4-1& GB14048.4 standards.
Except AC Contactor, there are many different types of low voltage electric appliances, such as Thermal Relay,Manual Motor Startor ,led light, Circuit Breaker, etc.
AC Contactor,Magnetic Contactor,Wafer Style Valve Wenzhou Korlen Electric Appliances Co., Ltd. , https://www.korlenelectric.com
