Optimal Skateboard Geometry for Maximizing Ollie Height

Optimal Skateboard Geometry for Maximizing Ollie Height: a Multi-Phase Direct Collocation Optimization Study

Heinen, Jan (TU Delft Mechanical, Maritime and Materials Engineering; TU Delft Biomechanical Engineering)

Moore, J.K. (mentor)
van der Kruk, E. (graduation committee)
ten Broek, Raymund (graduation committee)
van der Helm, F.C.T. (graduation committee)

Delft University of Technology

Biomedical Engineering

2022-12-20

Skateboarding involves a human controlling a four wheeled vehicle that is steered by tilting the standing surface. The riding mechanics of skateboarding have been well reported [2, 3]. The sport also includes aerial maneuvers such as jumping of stairs, flying off ramps and flipping and rotating the skateboard. The most basic aerial trick is called the ollie. The athlete jumps up while pushing down on the back end of the skateboard’s tail, causing a rotation about the back axle. The upward acceleration due to the rotation together with the tail-ground impact cause the skateboard to go airborne. Midair the athlete drags the skateboard up through frictional contact and levels it out to land the trick. The most concrete performance measure of the ollie is height according to the Olympic judging criteria [4]. To reach maximum height the dynamics such as impact, dynamic response, and torque production are dependent on shape, inertia and mass, which gives reason to assume an optimal shape exists. This leads to the research question: What are the optimal geometric and inertial parameters of a skateboard for an Olympic athlete to reach maximal ollie height. The skateboard geometry is optimized through multiphase direct collocation with the objective of maximal ollie height. A parameterized model is created with scaling mass and inertia properties such that the geometry of the skateboard. Modelling the dynamics of the ollie including impact and friction are done with a point mass human controller that is kineticly and kinematicly mapped to a counter movement jump. A simplistic contact implicit impact scheme is made for a higher order optimization. The ollie height is improved by changing the mass and inertia properties of the skateboard. Multiple optimal board shapes are generated for example a skateboard with a smaller wheelbase can reach higher ollie height compared to an industry standard skateboard.

Trajectory Optimization
Direct collocation
Skateboarding
Ollie
Parameter Optimization
Constraint friction model
Human jumper model

http://resolver.tudelft.nl/uuid:61f4e969-8bd1-4687-9942-b70024b216dc

52.00360,4.221259

https://github.com/mechmotum/ollie-optimization Github repository with code and data https://www.youtube.com/watch?v=jw5DmNnvD7c Video made of found optimization trajectories

Student theses

master thesis

© 2022 Jan Heinen