pyörämallia

Pyörämallia, meaning the wheel model, is a term used in Finnish engineering to describe mathematical representations of wheels and their interaction with a surface. It is employed to analyze and simulate the behavior of wheeled systems such as bicycles, cars, and mobile robots. A wheel model typically includes geometric properties (radius and width), kinematic quantities (rotational speed and linear velocity), and the contact mechanics between the wheel and ground, including friction and slip.

Two broad categories are common. Kinematic models assume rolling without slip and focus on the relationship between steering, acceleration, and wheel rotation. Dynamic or tire-level models include slip and friction forces, describing how input torques and steering angles translate into longitudinal and lateral motion. In dynamic models, slip ratio, slip angle, and tire forces are used to relate wheel dynamics to vehicle or robot motion. Realistic behavior is often represented with tire models, ranging from simple linear approximations to nonlinear formulas such as Pacejka’s Magic Formula for detailed simulations.

Applications of pyörämallia include vehicle dynamics analysis, such as stability, handling, and braking performance, as well as robotics and simulation in physics engines. The choice of model depends on the required accuracy and computational resources. In Finnish technical literature, pyörämallia appears in courses and documentation related to mechatronics, automotive engineering, and robotics, reflecting its role in design, control, and simulation of wheeled systems.