thyssenkrupp Stairlifts B.V. is part of the international thyssenkrupp group (one of the 30 biggest companies in Germany) and provides services relating to the design, production and product management of stair lifts for sales organizations around the world. Within this dynamic international environment, we combine experience, precision and quality awareness with excellent facilities and training opportunities and scope for innovation — producing people-to-people, "Made in Holland" technology. Our company is located near Rotterdam and has a workforce of over 150 employees. For more information about the organization and products visit our LinkedIn page: www.linkedin.com/company/thyssenkruppstairlifts.
The thyssenkrupp chairlift runs over an esthetic 80 mm mono rail that fits well in the interior design of our customers. The rail consists of a tube that guides the ride and a rack for propulsion. A smooth and steady ride up and down is what we want to provide to our customers therefor we apply a leveling system to achieve vertical position in transversal (rail) direction. The leveling in rail cross direction is mainly obtained by the geometric design of rail, drive and chair.
Stability in cross direction contributes significantly to the comfort that our customer experiences during the ride. The stability in cross direction for thyssenkrupp Stairlifts is ultimately determined by the position of the rack at the tube. User tests and measurements in our proto lab show that there is room for improvement in cross directional stability. Internal research already delivered possible counter measure to improve the comfort. However that needs further investigation to come to the root cause and we like to understand the behavior of our drive better
There has been a user test that generated the feedback that stability in cross direction, that contributes significantly to the comfort experience during the ride, could be improved.
Based on that result we carried out a performance test on stability in cross direction on a batch of identical rails. The batch volume was sufficient to rule out incidents like tolerance stack up and production deviations. The test consisted of continuous measurement of the seat angle while riding up and down over the rail.
The results showed unambiguous deviations in the seat angle for each rail at identical positions. The variance between the measurements on different rails was within small band width. This lead to the conclusion that there is a structural issue caused by a conceptual fact.
As a subsequent step we investigated the configuration and assembly processes of the rail. We purchase straight tubes that we cut to the right length and racks at a length dedicated to the rail part. A line is printed on the tube that represents the future rack position. The tube and the rail are separately bended in the right shape. The rack gets welded to the tube at the printed line. The complete process is controlled by a software application named Simcad that produces drawings and CNC files (i.e. position of the printed line) based on a 3D measurement of the customers staircase.
The result of this investigation was that, after some minor adaptions in Simcad (printed line position), the position of the rack on the tube after welding exactly matches the theoretical position. After the changes to Simcad a new rail identical to the earlier mentioned batch has been produced and tested but unfortunately there was only limited improvement. So the conclusion was drawn that the theoretical position of the line is not the optimum position in relation to cross directional stability.
Describe the behavior of the drive (bogie) during the ride over the rail in all its variety and its influence on the position and angle of the chair.
We want you to determine de optimal position of the rack on the tube with respect to cross directional stability of the chair. Taking in account:
Influence of inclination and bending of the rail
Flexibility of the construction under various loads.
Other relevant variables
We will determine the company standard on chair inclination and its tolerance one forehand in a separate project.
Translate the ideal position of the rack on the tube through algorithms from the 3D staircase measurement into output files from Simcad.
This is a complex project with many influencers. The project will take utmost from your analytical skills starting with describing concept and its dynamics. Once the dynamics has been described all influencers should identified and their effect be calculated in ratio of their influencers value. From this info a formula should be derived to calculate the position of the rack on the tube. Taking into account that the amount of rail variants is unlimited.
In stage 2 we appeal maximum to your logic for converting the relation between the influencers and the rack position into algorithms that generate the output CNC file for production.
Apart from the above mentioned competences we expect you to be able to work independently on this project. Of course you may count on sufficient guidance and support of your graduate supervisor.
For the execution of this project it would be beneficial if you master the Dutch language. Although our company language is English it will make the communication between yourself and employees relevant for this project easier.
Ideally we would like to have a team of two complementary graduates to execute the complete project however we can easily separate the different stages and divide it up into single person graduation assignments.
If, after studying the description, you want to have more information or apply for this thesis please contact one of the above mentioned contact persons.
Je studeert aan de TU in de richting Engineering.
Aan de slag bij thyssenkrupp Stairlifts
Je wilt graag aan de slag als stagiair bij thyssenkrupp Stairlifts. Stuur een mail met je motivatie en cv naar Stephan van der Sluijs (corporate recruiter a.i.) via de link: https://thyssenkruppstairlifts.recruitee.com/o/stagiair-afstudeerder-tu
Hij neemt op korte termijn contact met je op om de mogelijkheden te bespreken.