Computational Methods for Design, Planning and Verification regarding Deformable 1D Objects
Doctoral thesis, 2021
A topic of special interest is design, planning and verification regarding deformable 1D objects, such as electrical cables, wiring harnesses, hoses, pipes and tubes. These objects are geometrically characterized as one-dimensional (1D) in the sense that one dimension is significantly larger than the other two. Therefore, they usually exhibit large deformations when subject to external forces and moments, which may cause quality problems and unexpected geometrical interference between objects both in production and during the life-span of a product. Hence, it is of great industrial impact if problems with deformation can be addressed early in the virtual product realization process.
This thesis presents five computational methods for design, planning and verification regarding deformable 1D objects. The first two methods are targeted at routing design, i.e. finding a reference design and a routed configuration: one method for objects such as cables that may be significantly deformed due to gravity in their routed configurations and another method for preformed hoses that are not significantly deformed. The third method is in fact a methodology for performing variation analysis that in particular includes a method for generating tolerance envelopes. The fourth method is aimed at assembly verification, whereas the fifth method is aimed at production planning by performing path optimization for an industrial robot with a deformable dress pack. In summary, the methods allow for automatically finding a routed design, verifying the routed design with respect to both geometrical variation and assembly and improving operations in production with respect to deformation.
The main research challenge in developing the methods is to combine simulation of deformable 1D objects with iterative algorithms for path planning, variation simulation and optimization. For this purpose, a discrete Cosserat rod model is used to enable efficient and accurate computations of large deformations.
simulation of deformable 1D objects
Chalmers, Industrial and Materials Science, Product Development
Automatic routing of flexible 1D components with functional and manufacturing constraints
CAD Computer Aided Design,; Vol. 79(2016)p. 27-35
Hermansson, T, Åblad, E. Automatic routing of preformed hoses
Geometric variation simulation and robust design for flexible cables and hoses
Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture,; Vol. 226(2013)
Automatic assembly path planning for wiring harness installations
Journal of Manufacturing Systems,; Vol. 32(2013)p. 417-422
Quasi-static path optimization for industrial robots with dress packs
Robotics and Computer-Integrated Manufacturing,; Vol. 68(2021)
In the industry of today, virtual tools are widely used in the realization of a new product. As quality problems and late changes in the design and the production of the product can be extremely costly, much can be gained from discovering and addressing problems as early as possible using simulation. This holds specifically true when deformable 1D objects, such as electrical cables and hydraulic hoses, are involved. These types of objects are slender, or one-dimensional (1D), and are usually significantly deformed when subject to external forces and moments. This may cause quality problems and unexpected contact with other objects during both the production and the life-span of a product.
This thesis presents a set of novel methods for virtual design, planning and verification regarding deformable 1D objects. The methods allow for automatically finding a routed design of the object, verifying the routed design with respect to both geometrical variation and assembly and improving operations in production with respect to deformation. The methods rely on an efficient simulation model based on rod theory for computing deformations in accurate agreement with reality. As a result, the methods are today used at several global companies in the automotive industry, including Volvo Cars, BMW and Ford Motor Company. Together with existing virtual tools, they contribute to shorter development times, fewer physical prototypes and production test series and, in the end, a product of a higher quality.
Production Engineering, Human Work Science and Ergonomics
Areas of Advance
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 4909
Chalmers University of Technology
Opponent: Dr. Sotiris Makris, Department of Mechanical Engineering and Aeronautics, University of Patras, Greece