W Banas

The modular design of robotic workcells in a flexible production line

In the case of large-scale and mass production lines often the same model of an industrial robot is used in various places of the line and is intended to various task. However, the replacement of one industrial robot to another is a long lasting and arduous process. It requires stopping all the production line and sometimes even dismantling the whole workcell. Such situations are not frequent in production lines that are not flexible. They are related the most often with the failure on an industrial robot. However, during the designing of a flexible production line the ability to replace any robot, which is unrestricted, fast and trouble-free, greatly increase the flexibility level of such line. It could be realized by modular design of the proposed production line. In this way it could be possible to change any elements of such production system. But this approach needs to apply the specialized informatics system.This paper presents the obtained design of several versions of the same production workcell. Each, succeeding version of the designed production workcell contains more and more modular elements. Thereby it would be presented the evolution of a workcell design beginning from the typical design and ending with the fully modular one. One of tools needed to realize this task is the elaboration of a base of modules and typical joint and mounting elements that could be utilised in the described designing process. It is also presented the guidance information about the designing and programming processes useful at each stage of analysed process.

Modular industrial robots as the tool of process automation in robotized manufacturing cells

Recently the number of designed modular machine was increased. The term modular machine is used to denote different types of machinery, equipment and production lines, which are created using modular elements. Modular could be both mechanic elements, and drives, as well as control systems. This method of machine design is more and more popular because it allows obtaining flexible and relatively cheap solutions. So it is worth to develop the concept of modularity in next areas of application. The advantages of modular solutions are: simplification of the structure, standardization of components, and faster assembly process of the complete machine Additional advantages, which is particularly important for manufacturers, are shorter manufacturing times, longer production series and reduced manufacturing costs. Modular designing is also the challenge for designers and the need for a new approach to the design process, to the starting process and to the exploitation process. The purpose for many manufacturers is the standardization of the components used for creating the finished products. This purpose could be realized by the application of standard modules which could be combined together in different ways to create the desired particular construction as much as possible in accordance with the order. This solution is for the producer more favorable than the construction of a large machine whose configuration must be matched to each individual order. In the ideal case each module has its own control system and the full functionality of the modular machine is obtained due to the mutual cooperation of all modules. Such a solution also requires the modular components which create the modular machine are equipped with interfaces compatible one with another to facilitate their communication. The individual components of the machine could be designed, manufactured and used independently and production management task could be divided into subtasks. They could be also outsourced to an independent manufacturer. Standardization and run of the entire modular machine should be easier if standardized are individual modules. The advantages of modular design, in addition to those mentioned above, there are many more.

Agent-based models in robotized manufacturing cells designing

The complexity of the components, presented in robotized manufacturing workcells, causes that already at the design phase is necessary to develop models presenting various aspects of their structure and functioning. These models are simplified representation of real systems and allow to, among others, systematize knowledge about the designed manufacturing workcell. They also facilitate defining and analyzing the interrelationships between its particular components. This paper proposes the agent-based approach applied for designing robotized manufacturing cells.

Construction typification as the tool for optimizing the functioning of a robotized manufacturing system

Process of workcell designing is limited by different constructional requirements. They are related to technological parameters of manufactured element, to specifications of purchased elements of a workcell and to technical characteristics of a workcell scene. This shows the complexity of the design-constructional process itself. The results of such approach are individually designed workcell suitable to the specific location and specific production cycle. Changing this parameters one must rebuild the whole configuration of a workcell. Taking into consideration this it is important to elaborate the base of typical elements of a robot kinematic chain that could be used as the tool for building Virtual modelling of kinematic chains of industrial robots requires several preparatory phase. Firstly, it is important to create a database element, which will be models of industrial robot arms. These models could be described as functional primitives that represent elements between components of the kinematic pairs and structural members of industrial robots. A database with following elements is created: the base kinematic pairs, the base robot structural elements, the base of the robot work scenes. The first of these databases includes kinematic pairs being the key component of the manipulator actuator modules. Accordingly, as mentioned previously, it includes the first stage rotary pair of fifth stage. This type of kinematic pairs was chosen due to the fact that it occurs most frequently in the structures of industrial robots. Second base consists of structural robot elements therefore it allows for the conversion of schematic structures of kinematic chains in the structural elements of the arm of industrial robots. It contains, inter alia, the structural elements such as base, stiff members - simple or angular units. They allow converting recorded schematic three-dimensional elements. Last database is a database of scenes. It includes elements of both simple and complex: simple models of technological equipment, conveyors models, models of the obstacles and like that. Using these elements it could be formed various production spaces (robotized workcells), in which it is possible to virtually track the operation of an industrial robot arm modelled in the system.

Determination of the robot location in a workcell of a flexible production line

Location of components of a manufacturing cell is apparently an easy task but even during the constructing of a manufacturing cell, in which is planned a production of one, simple component it is necessary, among others, to check access to all required points. The robot in a manufacturing cell must handle both machine tools located in a manufacturing cell and parts store (input and output one). It handles also transport equipment and auxiliary stands. Sometimes, during the design phase, the changes of robot location are necessary due to the limitation of access to its required working positions. Often succeeding changes of a manufacturing cell configuration are realized. They occur at the stages of visualization and simulation of robot program functioning. In special cases, it is even necessary to replace the planned robot with a robot of greater range or of a different configuration type. This article presents and describes the parameters and components which should be taken into consideration during designing robotised manufacturing cells. The main idea bases on application of advanced engineering programs to adding the designing process. Using this approach it could be possible to present the designing process of an exemplar flexible manufacturing cell intended to manufacture two similar components. The proposed model of such designed manufacturing cell could be easily extended to the manufacturing cell model in which it is possible to produce components belonging the one technological group of chosen similarity level. In particular, during the design process, one should take into consideration components which limit the ability of robot foundation. It is also important to show the method of determining the best location of robot foundation. The presented design method could also support the designing process of other robotised manufacturing cells.

Experimental determination of dynamic parameters of an industrial robot

In an industry increasingly used are industrial robots. Commonly used are two basic methods of programming, on-line programming and off-line programming. In both cases, the programming consists in getting to the selected points record this position, and set the order of movement of the robot, and the introduction of logical tests. Such a program is easy to write, and it is suitable for most industrial applications. Especially when the process is known, respectively slow and unchanging. In this case, the program is being prepared for a universal model of the robot with the appropriate geometry and are checked only collisions. Is not taken into account the dynamics of the robot and how it will really behave while in motion. For this reason, the robot programmed to be tested at a reduced speed, which is raised gradually to the final value. Depending on the complexity of the move and the proximity of the elements it takes a lot of time. It is easy to notice that the robot at different speeds have different trajectories and behaves differently.

Modelling of industrial robot in LabView Robotics

Currently can find many models of industrial systems including robots. These models differ from each other not only by the accuracy representation parameters, but the representation range. For example, CAD models describe the geometry of the robot and some even designate a mass parameters as mass, center of gravity, moment of inertia, etc. These models are used in the design of robotic lines and sockets. Also systems for off-line programming use these models and many of them can be exported to CAD. It is important to note that models for off-line programming describe not only the geometry but contain the information necessary to create a program for the robot. Exports from CAD to off-line programming system requires additional information. These models are used for static determination of reachability points, and testing collision. Its enough to generate a program for the robot, and even check the interaction of elements of the production line, or robotic cell. Mathematical models allow robots to study the properties of kinematic and dynamic of robot movement. In these models the geometry is not so important, so are used only selected parameters such as the length of the robot arm, the center of gravity, moment of inertia. These parameters are introduced into the equations of motion of the robot and motion parameters are determined.

Analysis of the position of robotic cell components and its impact on energy consumption by robot

Location elements in the robot cell is very important must provide reasonable access to technological points. This is a basic condition, but it is possible to shift these elements worth considering over other criteria. One of them can be energy consumption. This is an economic parameter and in most cases its improvement make shorten the working time an industrial robot. In most conventional mechanical systems you do not need to consume power in standby mode only for a move. Robot because of its construction, even if it does not move has enabled engines and is ready to move. In this case, the servo speed is zero. During this stop servo squeak. Low-speed motors cause the engine torque is reduced and increases power consumption. In larger robots are installed brakes that when the robot does not move mechanically hold the position. Off the robot has enabled brakes and remembers the position servo drives. Brakes must be released when the robot wants to move and drives hold the position.

Modelling and simulation tooling controlled by the PLC in the robot cell in NX

Many CAD programs allows the simulation of machines. Often, before creating the real machine can simulate the operation and see how it works. In these cases, set values of the forces acting on an element or displacement of the element. It is very easy for simple machines. Programming in this way PLC controlled system is very complicated because have to save the the entire PLC logic in the simulation program. It would be good simply connect the PLC or PLC simulation program to a CAD program enabling the simulation. There are many possibilities for sending information between the PLC and CAD. PLC to control most of the actuators using the digital outputs 0 or 1. Actuators often have two states but the transition from one to the other takes some time. By setting additional parameters may be the behaviour of the simulation as in real life. Setting these parameters is usually held in the testing phase before running it means that the system is assembled and can be damaged. Often this is the only opportunity to verify the PLC program. It is worth noting that such testing and running takes place on the production line and needs to be stopped.

Modeling of a V-type mining support in an advanced engineering environment

Designing technical means using advanced computer systems requires the change in approaches to specific tasks carried out in this process. The solution of this problem is an integrative approach, which allows linking different operating ranges, various tools and complicated sets of requirements into a single operating design system. The elements of this integrative approach is the concept of splitting a technical mean system into three sub-system components. The first is structural sub-system containing solutions and their attributes regarding the structural concept of a designed system. The second is drive sub-system containing solutions of drive systems along with the parameters of their operation. Finally the last sub-system contains information relating to the control system and its settings. Systems attributes include such design features as the geometrical characteristics, material characteristics and assembly characteristics. The subject of the integrated design process is a mechanized mining support. As a part of the project the construction system of a mechanized mining support was divided on the three sub-systems. The structural subsystem includes a canopy, a burst shield and foot parts. Whereas the drive sub-system comprises includes the system of hydraulic props and hydraulic cylinders responsible for the functioning of the support. In the example, presented in the paper, is shown the system of hydraulic props where they are arranged in a V-system. These indicated two sub-systems form the structure of the support. It is complemented by the control sub-system basing on the use of control valves and separator valves and an operator control panel.