TWIKE 5 - Start of series development

Wow, that was more challenging than expected.

The concept phase took us quite a lot of energy and took a little longer than we initially planned. The results are impressive, and we are proud of what we have already achieved. We are also very glad for the successful cooperation of the whole development team and the supplying companies. Once again, we were shown the critical limits of such a development concept in all areas, especially about the complexity of a vehicle development. After all, every detail and decision regarding a component, a choice of material or a dimensioning is closely related to the adjacent component or the requirements of the assembly concerned. And all decisions are constrained by a matrix of boundary conditions, e.g. requirements regarding weight, manufacturability, availability, recyclability, costs or approval conditions.

Indeed, it is not complicated, just very complex.

Small changes or simple adaptations of geometry suddenly lead to time-consuming development loops, because a supposedly simple purchased part in the required version will not be available for us in the foreseeable future. This, in turn, results in a renewed search for a suitable component that can ensure suitability and availability. At the same time, it means obtaining CAD data and and if necessary, scanning and reversing it to readable data by the CAD system and re-adjusting the development at this point. Finally, this must be coordinated with the adjacent surfaces or components. Even in a great team under time pressure, this can result in grey hair.  But we have been able to achieve very good results in the last three months. And with these ones we are now going into series development.

Although the first simulations were already carried out in the concept phase and these already provided valuable information on critical load paths of the frame structure, it is now time for the calculators once again. The CAD data of the body-in-white created in the concept phase will be checked for plausibility and discontinuity, networked and subjected to forces known from typical crashes as well as from known driving load cases, and thus be verified for their suitability. We understand that there is no social acceptance about absolute safety in an automobile.

CAE (Computer Aided Engineering) tools are however a very good manner for optimizing vehicles in terms of their protective function and associated dimensions and the resulted weight. The calculation results flow back to the design in multiple rounds, which adapt the design considering the targeted total weight and the target center of gravity position and modify it until an optimum result can be confirmed. In parallel, the production processes are already being planned in greater detail, the material flow is being defined, the space required for the production processes is being determined, the purchasing conditions and delivery lot sizes are being agreed in initial contracts, the qualifications of the employees working in production are being determined and the logistical flow of incoming materials and vehicle provision is being planned. The approval procedure is also prepared by collecting the first documents of the testable components and comparing the documentation with the legal approval requirements. These have become much more stringent in recent years, causing considerable additional work in documentation and in some cases driving up component prices, as more stringent requirements must be met on the supplier side.

Indeed, it is not complicated, just very complex.

The figure shows an X-ray view of the current design status. The frame structure shown in the dark will be manufactured in the next few weeks and assembled with all driving-relevant components to form the driving test vehicle (FET). The drive components and all components of the EE architecture relevant for the FET are in parallel work and the anticipation of the first test drive already makes our hearts beat faster.

Updates will follow.