Robotics for small and medium enterprises: control and programming challenges
J. Norberto Pires is based at Mechanical Engineering Department,University of Coimbra, Coimbra, Portugal
Robotics for small and medium enterprises: control and programming challenges
Robotics is one of those subjects that leave nobody indifferent. No matter if they are used to work in industry or at our homes, mimic some of the human capabilities, or used to access dangerous environments, launched to space, or simply used to play with, robots are always a source of human interest and admiration. Here, the focus is on robots used to work on industrial environments, i.e. robots built to substitute man on certain industrial manufacturing tasks being a mechatronic co-worker for humans.
In fact, actual manufacturing setups rely increasingly on technology. It is common to have all sources of equipment on the shop floor, commanded by industrial computers or PLCs connected by an industrial network to other factory resources. Also, the manufacturing systems are becoming more and more autonomous requiring less operator intervention in every day normal operation. That is a consequence of actual market conditions, characterized by a global competition and a strong pressure for better quality at lower prices, with products defined in part by the end-user costumers. This means producing in small batches, never risking long stocks, and working to satisfy already placed costumer orders. Consequently, concepts like flexibility and agility are fundamental in actual manufacturing plants, requiring much more from the systems used in the shop-floor. Flexible manufacturing systems take advantage of being composed by programmable equipment to implement most of its characteristics, which are supported by reconfigurable mechanical parts. Industrial robots are good examples of flexible manufacturing systems. Using robots in actual manufacturing platforms is, therefore, a decision for flexibility and a way to increase the agility of the manufacturing process. If the manufacturing processes are complex, with low cycle time and have a lot of parameterization due to the diversity of products, then using robots is the correct decision, although it is not enough for a complete solution. In fact, engineers need to integrate other technologies with the objective of extracting from robots the flexibility they can offer. That means using computers for controlling and supervision of the manufacturing systems, industrial networks and distributed software architectures. It means also designing application software that is really distributed in the shop floor, taking advantage of the flexibility installed by using programmable equipment. Finally, it means taking special care of the human-machine interfaces (HMI), i.e. the devices, interfaces and systems that enable humans and machines to cooperate on the shop-floor as co-workers taking advantage of each-other capabilities.
Also, the robot and robotic cell programming task would benefit very much from improved and easy to use interaction devices. This means that availability of SDKs and/or programming libraries supported under common programming environments is necessary. Application development depends very much on that.
Working on future SMEs means considering humans and machines as co-workers,on environments where humans have constant access to the manufacturing equipment and related control systems.
Several devices are available for user interface (several types of mouse,joysticks, gamepads and controls, digital pens, pocket PCs and personal assistants, cameras, different types of sensors, etc.) with very nice characteristics that make them good candidates for industrial use. Integrating all this devices with current industrial equipment requires the development of a device interface, which exhibits some basic principles in terms of software,hardware and interface to commercial controllers.
This scenario can be optimized in the following concurrent ways:
Develop user-friendly and highly graphical HMI applications to run on the available interface devices. Those environments tend to hide the complexity of the system from the operators, allowing them to focus on controlling and operating the system.
Explore the utilization of consumer input/output devices that could be used to facilitate the operator access to the system. In fact, there is a considerable amount of different devices on the market developed to use with personal computers on different input/output tasks. Such devices are usually programmable, with the manufacturers providing suitable SDKs which make those devices suitable for further exploitation with the objective of integrating them with industrial manufacturing systems.
Explore the functionality of the available software packages commonly used for engineering. Good examples of those packages are the CAD packages used by engineers involved in design and project activities, to develop, optimize or improve their designs. Since the vast majority of companies use CAD software packages to design their products, it would be very interesting if the information from CAD files could be used to generate robot programs. That is,the CAD application could be the environment used for specifying the way the robots should execute the required operations on the specified parts. Furthermore, since most engineers are familiar with CAD packages, exploring CAD data for robot program and parameterization seems to be a nice way to proceed.
These and other challenges are objective of the SMEROBOT Consortium, an IP project financed by the European 6th Framework R&D program. For details visit the web site: www.smerobot.org
