38. Designing a robotic welding cell for bus body frame using a sustainable way
1Instituto Superior de Engenharia do Porto, Portugal; 2INESC TEC, Rua Dr. Roberto Frias, 4200 - 465 Porto, Portugal
The implementation of automatic systems to execute tasks on the automotive industry brings many advantages when compared to humans. Although the increased productivity is a significant improvement, it is not the main reason to replace humans for autonomous systems. The quality and reliability emerge as important advantages in the use of automatic systems. Since safety became the number one priority of European standards, the quality factor has an enormous importance in the automotive industry.
Besides the most common vehicles which are mass produced by the largest automotive groups, special vehicles, such as buses, ambulances and garbage trucks among others, circulate daily on the roads around the world. These types of vehicles are produced by smaller companies that are specialized in a certain genre of vehicles.
The small quantities of the production series and the high rate of customization per client make it impossible to use fully automated production lines. However, the legal requirements to produce these vehicles specify dimensional accuracies and quality grades that are becoming harder to achieve with human workers. These companies are finding the solution for this problem by using flexible manufacturing cells that are able to execute the most critical tasks.
This study aimed to determine the advantages of using a robotic welding cell to produce bus body structures and to follow its implementation in the production process. In order to make a reliable data comparison, it is chosen a part from the bus’s luggage to execute all necessary tests. Furthermore, the use of a robot out of service was also studied because the robot already owned presents the characteristics needed for this kind of service, allowing an enhancement of the project performance and ensuring the reusability and life-extend of some important and expansive tools.
The method includes the development of a software simulation, one test using the robotic cell and ten tests using a human worker. The cycle time measured by the robotic cell is considered as a constant and the cycle time for a human worker is given by the average of the ten measures. The setup time is not considered for this study due to the possibility of using the same jigs for both tests. The test pieces are evaluated recurring to non-destructive and destructive tests to gather information about the quality of the welded joint: porosity, penetration and finishing.
At the end of this study, a significant reduction on the time needed to produce one component was achieved, as well as significant improvement on the product’s quality. The reduced cycle time brings an economical benefit: lower cost of manufacturing and higher profits allows the company to evolve into new markets and clients. The reduction is expected to be significant, allowing for a quick payback of the investment. The quality improvement is achieved by the highly precise manufacturing process, which is possible due to the robotic control. This key advantage enhances the company's competitiveness and makes possible to fulfill the increasingly demanding European standards.
198. Opportunities for robotic automation in wood product industries: The supplier and system integrators´ perspective
1Linnaeus University, Sweden; 2Department of Mechanical Engineering, Linnaeus University, Lückligs plats 1, 351 95 Växjö, Sweden; 3Technology Management and Economics, Chalmers University of Technology, Vera Sandbergs Allé 8, 412 96, Gotheburg, Sweden
In many industries, the automation of manufacturing processes is seen as an appropriate way to stay competitive, to increase market shares or to avoid outsourcing to low-cost countries. This is often achieved by the implementation of flexible manufacturing systems such as industrial robots. However, in industries with low or even no experience of the utilization of automation, discrepancy between what is requested by a company and what is actually the best way and feasible to fulfill these demands, could be observed. Company leaders are often interested in automating the most complicated processes in their production, making an automation project hardly performable and practical. This phenomenon can be witnessed when attempting to copy successful automation projects from other industry sectors to industries with little to no experience of automation such as wood product industries without understanding crucial underlying factors such as programming time and cost, additional equipment or the personnel´s competence. In many cases this can result in poor experiences and lost trust in new technologies. Understanding and acquiring knowledge about vital automation factors from an automation perspective are therefore important for wood product industries in order to achieve successful automation.
In this qualitative research, several sales engineers of robot manufactures and robot system integrators were interviewed to gain insight into possibilities, opportunities and applications for robotic automation of different wood product industries. Thematic and content analysis of the interview data was conducted as part of the data for gaining relevant results.
Results indicate that system integrators and robot manufactures do not see any technical or material based hinders for wood product industries to automate. However, opinions about what and how to automate differ a lot. In wood product industries the complex and complicated tasks are prioritized with respect to automation, while system integrators tend to start with simple applications in order to get a solid start. As one of the reasons for this discrepancy, the lack of experience of utilizing automation equipment by production managers in wood product industries is identified. Often, they are not aware of their possibilities and opportunities where and when to gain the biggest production improvements, both for worker´s workload and for production efficiency. In addition, the benefits of using flexible industrial robots in production systems will be discussed.
264. New Motion Control approach for synchronized handling of complex parts
Vigo University, Spain
Machinery for parts manipulation (picking, pick to place, etc.) is one of the most demanded processes in many industry sectors, from agroalimentary to industrial manufacturing. Among these types of processes, one of the most in demanded is the separation and individualization of parts of a bulk set in order to place each one into separated containers.
At present, the picking problem is solved with different technologies. Handling not a problem if parts have fixed forms and fixed mechanical properties, which facilitates their manipulation with vacuum suction pads or specifically designed clamps. These elements are often installed in robots (delta robot, cartesian robots, anthropomorphic robots, etc.). The most common industry solution is the use of Delta robots driven by artificial vision systems to detect the position of incoming parts. These positions are continuously recalculated as the parts transportation system moves-as this movement is sensed by encoders.
However, heteromorphic pieces are difficult to grasp by clamps, and vacuum suction is not suitable in the case of specific product properties: slippery parts, soft parts, frozen parts, etc. Sometimes, a high cadence of parts make unsuitable solutions based on the use of delta robots. For these, mechanical pushers or blower can be used. But it is not possible to get a precision part positing by pushing and blowing when working fast, and especially when dealing with sleepy parts (as frozen, oiled ones) since is not possible to accurately predict the final speed or position.
Therefore, push or blow cannot be used when working with sliding products and parts (position parts) have to be synchronize with a second output line. Sometimes, to get that synchronism, successive belts at different speeds, which are slowed and accelerated are used. The drawback is the sliding of the pieces and the cadence.
None of the mentioned methods allow the synchronous positioning with products with complex morphological and dynamic characteristics. This paper addresses this problem. The paper proposes a new handling methodology based in a double strategy. First, the clamping of the piece by adjusting two controlled barriers to part dimensions, to later proceed to a part translation by push and/or retention, to be able to deposit the part in a output line in a synchronous way.
The paper presents the mechanical and control principles of the proposed new manipulation method. The control algorithm is described. It uses standard motion control blocks (MC_PLCOpen), although there is no block that solves the proposed functionality by itself, so a new one is developed. Moreover, a prototype implementation and the experiments results are presented. Finally, taking into account the requirements of a typical industrial application, the functional viability of the new system is analyzed.