Unison has launched an advanced three-dimensional simulator to help metal fabricators accelerate the development of control programs for all-electric tube bending machines. Using artificial intelligence techniques, the simulator provides powerful program analysis and optimisation facilities, together with realistic real-time visualisation of the tube bending process.
The simulation software is valuable in almost all tube bending applications, but can be particularly helpful for fabricators quoting on jobs and planning production, in reducing design-to-manufacturing times to help speed product delivery, and on any application involving tubes manufactured from expensive alloys. Customers with several Unison machines can also use the software to choose the most appropriate machine for bending a particular part.
Based on true CAD models of the target machines, resulting in exceptionally detailed computer-generated imagery, Unison’s new 3D simulator is designed specifically to help users develop high quality production-standard tube bending programs without the need to test and optimise them on the target machine. Used in conjunction with Unison’s Windows-based Unibend control software, it enables fully validated bending programs to be created entirely off-line, and is suitable for any machine in the Breeze range of all-electric tube benders.
One of the most time-consuming tasks normally faced by users is structuring the program to prevent any collisions between the tube and the bending machine, or its surroundings such as the production floor. Optimising the program’s bending sequence and incorporating any necessary correction feeds for collision avoidance is usually an iterative task demanding valuable machine time. It also invariably involves producing trial parts, creating unnecessary scrap material.
Unison’s 3D simulator incorporates fully automated collision detection capabilities and offers a choice of real-time or batch operating modes to create error free bend instructions. In real-time mode, simulation can be paused at any time and can be started from any bend; changes made to bend instructions will cause the simulator to re-evaluate the motion profile of the machine – ensuring that the simulator always mirrors the sequences used on the real machine. In batch mode, the simulator will study a directory tree and process all bend instruction files in that tree; parts that can be bent will be stored in a designated folder and parts for which the simulator could find no collision-free solution will be stored in a quarantine folder for further analysis by production or design teams.
Without simulation, ascertaining whether it is even possible to bend a part on a particular machine can take several days. Unison’s 3D simulator shortens the design-test-optimise process dramatically, eliminating the need for a bending machine and its operator until manufacturing commences. For example, designers can now typically verify whether a part can be bent within about 3 minutes.
Users can save the results of simulations and rerun them at any time for comparison purposes. Artificial intelligence (AI) techniques are employed to help users select the most efficient bending sequences and optimise them to minimise machine cycle time. The simulator’s AI is aware of the capabilities of the machine and can work through all permutations very quickly.
Unison believes that it is very important to ensure detection of every collision, and the company’s software development team has written a custom physics engine that is accurate to 0.005 mm. Whilst this is in advance of the mechanical accuracy of real machines, customers surveyed opted to have highly accurate simulation with the option to ‘ignore’ a collision rather than use a tolerance, which could lead to missed collisions. All types of collisions are detected in the simulator, including tube on tube, tube on environment, tube on machine, machine on machine and tube spring-back.
To maximise bend accuracy, the simulator factors in the tendency for metal tubes to spring back after being bent. There are two elements to spring-back correction; a proportional element which is determined by the programmed bend angle, and a fixed element which depends on the type of tube material and its size and thickness. The value of the fixed element is based on empirical data held in a materials database, which the user can update when testing new batches of raw material, or as a result of sampling production parts under a quality assurance programme.
According to Unison’s Jim Saynor, real-time 3D simulation of tube bending allows metal fabricators to achieve significant cost savings through much faster program development and reduced scrap. The new simulator provides a much more detailed and realistic portrayal of machine performance than competitive software, providing users of Unison all-electric tube benders with a major business advantage.