Virtual Exercise Machine (VEM).
A VEM is a program that represents the behavior of a physical machine, i.e. a bike, within an application on a computer. Each virtual machine contains its own configurable equipment characteristics (frames, gears, tires, etc.) as well as a representation of physical forces (such as gravity, inertia, air density, etc.).
Such a reference model guarantees that the use of the actual equipment always feels ‘right’ in a dynamic, digital environment. Multiple Virtual Exercise Machines can run simultaneously on the same device or in the cloud, which makes the VEM-based approach ideally suited for multi-player and simulation uses.
Digital Force Control (DFC).
We developed a patent-pending way to algorithmically replicate the ‘on-pedal’ feeling of physical forces such as air and rolling resistance, slope, weight, air pressure, wind speed, temperature, altitude, inertia, acceleration, braking, etc.
The set of control algorithms needed to achieve this are complex. They produce co-dependent variables such as masses, friction coefficients, damping coefficients, geometrical dimensions, the direction of the gravity vector. and define the performance of the VEM.
Close-loop stability guarantees robust and reliable performance and insensitiveness to noise and external disturbances. As a result, the ‘physics’ a cyclist encounters on the road, off-road, in a velodrome, etc. are computed to achieve a true simulation.
Resistance Control Mechanism (RCM)
The RCM is a digitally controlled, electromagnetic device replacing analog, friction-based flywheels. That way computations of the VEM can be actuated and controlled with unique accuracy and speed in a resistance simulator.
The resistance profile and responsiveness of the mechanism provides a realistic feel of real-world behavior, including – crucially - the sensation of inertia, which is delivered through managing the resistance profile. This sense of inertia means that the resistance profile can be used both for aerobic and resistance training.
We use modern cloud infrastructure for scale such as multi-user environments, as well as advanced services such as equipment performance monitoring, service diagnostics and firmware upgrades.
All together now
Altogether this arrangement – VEM, DFC, and RCM - provides a highly accurate and digitally configurable control architecture. It can measure resistance at a sample rate of 2KHz. The drive and sensor arrangement can also set spot resistance at a rate of 2KHz, whilst mapping the desired resistance level at any moment in time to a physics model. All the control parameters are governed by a control program that monitors the torque and is in turn controlled by a mobile device. The device provides the user interface, records data, and links input resistance to media, such as videos and games.
This architecture saves costs by reducing the need for hardware such as drivetrains and power meters, enables new possibilities such as simulations, games, benchmarks, etc. and delivers an ‘on-pedal’ feeling that is truly realistic.