Jochen Bönig

Methodical integration of assembly specific influences concerning high-voltage components into the virtual validation process

The future competitive situation in the automotive industry and the increasing market demands will inevitably lead to higher complexity in product development, production planning and pre-series. Longer lifecycles of assembly systems based on highly flexible production cells with a rising number of integrated processes call for new challenges, especially for production engineering. One key challenge for gaining important time and cost potentials in production engineering projects is an early virtual validation during the pre-series. Under the premise to replace physical mock-ups by digital mock-ups, we will present requirements and solutions of a virtual validation focused on manual assembly of high-voltage components in the automotive industry. We want to integrate the electric drive used for electric and hybrid vehicles into the computer aided design based virtual validation process. This paper presents a product and process validation methodology for a prototype electric drive, using a virtual human model. For this, an electric drive is dismantled and the necessary assembly steps are identified. Further, two process-steps, i.e. packaging of electrical sheets and insertion of magnets, are selected and a virtual validation concept is developed. Using a virtual human model, ergonomics are included as an essential part of the product and process validation methodology.

Explicit dynamics process simulation of linear coil winding for electric drives production

Slowly but steadily, more and more electric vehicles push onto the consumer market. For a cost efficient production of electrical engines, in first-class quality and in sufficient quantity, it is indispensable to understand the process of coil winding. Thereby the prediction of the wire behavior is one of the key challenges. Therefore, a detailed model is built to investigate wire behavior during the linear winding process. The finite element based simulation tool LS-DYNA serves as explicit dynamics tool. To represent the high dynamic process of winding within this simulation, some first adaptions have to be made. This means, that dynamic influences such as rotational speed or acceleration of the coil body are definable. Within process simulation, the given boundary conditions are applied to the model. The material properties of the wire under scrutiny are validated by a tensile test and by the values out of datasheets in previous research. In order to achieve the best convergence, different contact algorithms are selected for each individual contact behavior. Furthermore, specific adjustments to the mesh are necessary to gain significant results. State of the art in coil winding is an experimental procedure, which delivers adequate process parameters and, thus, expertise in winding technology. Nevertheless, there are a lot of different, interacting parameters, which have to be optimized in terms of boundary conditions. The simulation model of winding process, in which varying parameters can be optimized pertaining to the optimal winding result, calls for extensive research in this field. The generated model enables the user not only to influence the process parameters but also to modify the geometry of a winding body. To make the simulation scientifically sound, it is validated by previous experiments and simulations

Simulation of orthocyclic windings using the linear winding technique

A continuously rising number of electric vehicle licensing is mentioned since the last few years in Germany. For a cost-efficient production of electrical engines in first-class quality and in sufficient quantity, it is indispensable to understand the process of coil winding. Thereby, the prediction of wire behavior is one of the key challenges. Therefore, a detailed model is built to investigate wire behavior during the linear winding process. The finite element based simulation tool LS-DYNA serves as explicit dynamics tool. The tool works with an explicit time integration method for time discretization. To represent the high dynamic process of winding within this simulation, dynamic influences such as rotational speed or acceleration of the coil body are definable. Within process simulation, the given boundary conditions are applied to the model. The non-linear material properties of the wire are validated under scrutiny by a tensile test and by values out of datasheets in previous research work. Simulation results of orthocyclic windings using the linear winding technique are presented within this paper. The dynamic simulation model is validated by experiments using the caster angle of the wire guide as reference parameter. The caster angel rises during the winding process of the first layer until the wire jumps to the next layer. Hence, it is possible to identify the maximum caster angle and match the simulation value against the experiment value. The travel profile of the wire guide is identified as extremely important to generate an orthocyclic winding. Another substantial part is the wire fixation respectively the geometry to support the first winding offset from winding one to winding two. Results of orthocyclic windings are simulated with and without grooves on the coil body surface and demonstrate the positive influence of grooves for an accurate orthocyclic winding picture.

Virtual Validation of the Manual Assembly of a Power Electronic Unit via Motion Capturing Connected with a Simulation Tool Using a Human Model

A key challenge for gaining important time and cost potentials in production engineering projects is an early virtual validation during the pre-series. Under the premise to replace physical by digital mock-ups, we will present requirements and solutions of a virtual validation focused on manual assembly of power electronics in automotive industry. Using a digital human model for dynamic analysis is not very prevalent, because of the high modeling complexity in the digital environment. The resulting motions of the human model are furthermore unrealistic. Hence the need for research is a time saving and, regardless, a realistic movement design for virtual validation by a human model. To achieve this goal, we use an experimental setup including a variable eight camera motion capture system, a data glove and an interface for the connection to the digital validation software.

Worker information system to support during complex and exhausting assembly of high-voltage harness

There are a lot of different kinds of electric drives and each category has a different installation position within a vehicle. A huge number of variants pose a challenge for manual assembly as the varying constellations of high-voltage (HV) cables require individual assembly steps. A worker needs information both about a vehicle and about HV components with their properties. We obtained good results for this on base of a worker information system (WIS). We can visualize parts assembly using three-dimensional (3-D) objects. The results of hazard analysis are shown in text format. But a WIS lacks in representing the physical behavior of parts within assembly. Especially HV cables move in an undetermined way when they are handled. We have an approach to simulate HV cables within assembly simulation. The material properties of HV cables during distortion are calculated in a finite element analysis (FEA). These parameters flow into an assembly simulation containing flexible parts like HV cables and a digital human model. The results of simulation runs can not only be used for assembly planning but also for worker guidance. We present an approach how to qualify simulation results for import to a WIS. In addition, possible application scenarios for such a WIS are explained.

“Human-In-The-Loop”- Virtual Commissioning of Human-Robot Collaboration Systems

Human-robot collaboration (HRC) has the potential to increase the degree of automation, and thus productivity, throughout many industries. However, complex safety considerations and a lack of appropriate planning tools still prohibit a more widespread application. In this paper, the use of virtual commissioning (VC), an established tool for the validation of common automated systems, for the validation of HRC-systems is proposed. For this, the structure of a traditional VC environment is combined with a digital human model (DHM). To ensure adequate behavioral fidelity, a real-time overlay of human action and the virtual automated system, using motion capture technology, is imperative. This also requires the live visualization of the simulation environment via virtual reality (VR). The structure of such a simulation system is presented and evaluated. Furthermore, the cost and benefit for this new method is contrasted.