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Ark-dynamics-6dof-motion-simulation-platform-Stewart platform

PDK Patent (CA 3217174 C)

Patent Overview

Patent Number: CA 3217174 C Title: Motion Simulation System and Method / Procédé et Système de Simulation de Mouvement Issue Date: February 11, 2025 Inventors: Louis Hajichristou and Michael Gregoriades (Cyprus) PCT Filing Date: February 8, 2023 Priority Date: February 9, 2022 (US provisional)

Key Technical Innovation

This patent describes an innovative motion simulation system that separates weight-bearing and positioning functions to achieve better performance and cost efficiency. The core innovation involves:

  • Weight Bearing Actuators: Pneumatic cylinders that support the payload weight

  • Positioning Actuator Assemblies: Rotary actuators that control platform position

Technical Components

Weight Bearing System

  • Pneumatic cylinders with pistons that create pressurized volumes

  • Can include buffer tanks to provide 100-500% additional dead volume

  • Minimizes pressure variations and actuation force changes

  • Can be calibrated to support platform at desired positions

Positioning System

  • Rotary actuators (motors) with stators and rotors

  • Connecting rods with optional cranks

  • Can operate at frequencies up to 1000 Hz

  • Provides 6 degrees of freedom (surge, sway, heave, roll, pitch, yaw)

Control System

  • Controller detects positioning actuator current draw

  • Pressurizes pneumatic cylinders to minimize positioning actuator load

  • Can use closed-loop control with rotary encoders

  • Supports various control modes (forward/inverse kinematics)

Key Advantages

  • Energy Efficiency: Positioning actuators don't constantly bear weight

  • High Frequency Response: Up to 1000 Hz operation

  • Cost Reduction: Smaller, lighter positioning actuators

  • Energy Recovery: Can regenerate energy during motion

  • Improved Stiffness: Direct-drive mechanism increases system rigidity

Configuration Examples

  • The patent describes multiple configurations:

  • 3 weight bearing actuators + 6 positioning assemblies (standard hexapod)

  • Various symmetric and asymmetric arrangements

  • Integrated linear actuator units combining both functions

  • Haptic device implementations for human-machine interfaces

Motion Envelope

  • Travel limits: -100mm to +100mm (some configurations)

  • Angular limits: ±15° to ±20° in roll/pitch/yaw axes

  • Swivel angles for ball joints: ±10° to ±20°

Applications

  • Motion simulators (flight, driving, gaming)

  • Amusement park attractions

  • Virtual reality systems

  • Haptic feedback devices

  • Low-mass applications without weight bearing actuators

This patent represents a significant advancement in motion simulation technology by decoupling the weight support and positioning functions, enabling more efficient, responsive, and cost-effective motion platforms compared to traditional Stewart platform designs.

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