Rocker-Based Motion Generator for High Bandwidth Simulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current motion systems, particularly those used in high-end applications like military and commercial flight training, are large, heavy, complex, and expensive, with limitations in bandwidth and responsiveness due to high friction and inertia.
Innovation Solution
A motion generator design featuring a parallel manipulator with elongate rigid struts connected to rockers, which are actuated by belt, cable, rope drives, or linear motors, minimizing friction and inertia while providing high bandwidth and responsiveness in all six degrees of freedom.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional Stewart platform motion generators are used, then six degrees of freedom motion capability is achieved, but the system becomes large, heavy, and complex with high friction and inertia
Solution Approach 1:
The motion generator is divided into multiple independent rocker mechanisms, each responsible for specific degrees of freedom. Each rocker is actuated by its own actuator, allowing independent control and reducing the complexity of the overall system while maintaining six degrees of freedom capability
Solution Approach 2:
The patent introduces a novel rocker-based mechanism that transforms the traditional parallel manipulator architecture. By using rockers with pivot axes and elongate struts connected to effectors, the system achieves motion in multiple dimensions through rotational movements around pivot axes, rather than traditional linear actuation
2Force
If traditional motion generators with high mass are used, then payload support capability is improved, but bandwidth and responsiveness deteriorate
Solution Approach 1:
The patent replaces traditional high-mass mechanical linkages with a rocker-based mechanism that uses rotational pivots and elongate struts. This substitution reduces the moment of inertia and friction while maintaining the ability to support payloads, thereby improving bandwidth and responsiveness
Solution Approach 2:
The design changes the mechanical parameters of the motion generator by using rockers with optimized pivot axes and elongate struts. This configuration reduces the effective mass and friction in the system, allowing for higher bandwidth operation while maintaining payload support capability
3Measurement precision
If precision mechanical linkages are used, then motion control accuracy is improved, but friction and inertia increase
Solution Approach 1:
The patent extracts the essential motion control function from complex precision mechanical linkages and implements it through simpler rocker mechanisms with pivot axes. This extraction maintains motion control accuracy while removing unnecessary mechanical complexity that would increase friction and energy loss
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The proposed motion generator achieves high bandwidth, typically above 50 Hz, with low friction and inertia, enhancing the accuracy and naturalness of motion simulation experiences for human users.
Implementation Method 1
minimizing friction and inertia while providing high bandwidth and responsiveness
Implementation Method 2
the actuator being in the form of an elongate belt, cable, rope drive, or linear motor
Data Source
AI summary
According to a first aspect of the invention there is provided a motion generator comprising an effector for applying forces, moments and movements to a payload relative to a surface connected to one or more elongate rigid struts, each strut being connected at one end thereof by a first joint to the effector and being connected at its other end by a second joint to an associated rocker, the rocker having a pivot axis, such that movement of a rocker about the pivot axis leads to movement of the effector, and forces applied to an associated rocker lead to forces being applied to the effector, in which the movement of a rocker and forces applied by the rocker are controlled by an actuator, the actuator being in the form of an elongate belt, cable, rope drive, or linear motor arranged to apply a force to a point on an associated rocker away from the pivot axis of the rocker. According to a second aspect of the invention there is provided a motion generator comprising an effector for applying forces, moments and movements to a payload relative to a surface, the effector being connected to four, or more elongate rigid struts, each strut being connected at one end thereof by a first joint to the effector and being connected at its other end by a second joint to an associated rocker, the rocker having a pivot axis, such that movement of a rocker leads to movement of the effector, and forces applied to an associated rocker lead to forces being applied to the effector, in which the movement of a rocker and forces applied by the rocker are controlled by an actuator, the actuator being arranged to apply a force to a point on an associated rocker away from the pivot axis of the rocker. The invention also relates to motion systems, and driving simulators including such motion generators, and to methods using such motion generators and systems.