In order to make a positive contribution to the development of this industry and to the process itself, a new machine is being developed by the Department of Mechanical Engineering  at the University of Aveiro intending to take the potential of this process to the highest level.​

This project and consequently the machine have received the name of SPIF-A. SPIF stands for Single Point Incremental Forming and the A stands for Aveiro.
This project was initiated in 2010 and it involves the design of a dedicated machine based on a parallel kinematics. The use of hydraulic power and parallel kinematics allows the machine to have six degrees of freedom while withstanding high loads at the tool. The use of a parallel kinematics, more specifically a Stewart Platform, is a new approach to the SPIF industry.

To assess the forces developed during SPIF process it was designed a force measuring configuration composed by three load cells placed between the spindle and the Stewart platform’s mobile base. These load cells can measure forces in the three main axes X, Y, Z and bending moments in two additional axes X and Y.

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The great technical challenge of this project is the measurement and control of all the different factors such as the position, speed, acceleration of the tool and the measurement of forces and moments occurring during operation. Since all that information comes from different sensors it was necessary the use of a technology that allowed the input and output of different types of signals, (analog and digital).
Additionally, by its nature, parallel kinematics involves complex calculations in order to achieve a rigorous control of the tool. In order to overcome that, it became necessary the use of hardware capable of effectively processing all the information within the desired cycle time.
Given all those requirements a Speedgoat real-time performance machine was adopted. This choice allows high real-time performance, the capability of receiving/sending analog and digital signals and having I/O expansion flexibility, it also results in the reduction of the necessary hardware.
Another advantage in the use of Speedgoat products is the centralization of programming software. The use of Matlab and its embedded tools allowed the development of a simple and customizable interface between the user and the machine. This interface is divided in two steps.

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The first step uses a computer where a Graphic User Interface (GUI) developed in Matlab is executed and from where a user can control and program the machine. The GUI allows the user to control the machine directly, by the use of a joystick or by entering code straight in to the machine’s memory (manual data input), or indirectly by loading and executing a tool path pre-generated in a CAM software.

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The second step uses the real-time target machine for execution of commands and control of the machine. The real-time target machine executes software developed in Simulink. The use of Simulink was a great advantage because it allows fast programming and quick debugging. This software is the core of the machine control system. This software is responsible for all the control aspects but it also includes all the fail-safes systems and safety protocols.
 

By working in a closed-loop control the system becomes more accurate and unaffected in the presence of external noise sources. This software also relays the information received from the different sensors of the machine to the Graphic User Interface.
The use of a two-step system permits the user to multitask while the forming operation takes place. Since the communication of the two machines is made by TCP/IP, the information can be sent to more than one Graphic User Interface allowing more than one user to oversee the state of the work.

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