Curvilinear Track Position Sensing for Smooth Linear Motor Traversal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional linear motor systems face challenges with curvilinear track sections, including motor coil arrangement, unwanted forces due to 'jerk' during curved traversals, difficulty in tracking moving elements, and complexity in transitioning between curved and straight sections, which affect stability and efficiency.
Innovation Solution
A method for manufacturing curvilinear track sections with angled slot groupings and motor units, providing a sinusoidal angular velocity profile and clothoid profiles to minimize jerk, and using a wedge aligner to compensate for stack-up tolerances, allowing for smooth transitions and high-speed operation on curved sections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional linear motor systems use standard motor coil arrangements, then the system structure is simple, but the system cannot properly handle curvilinear track sections with varying radii
Solution Approach 1:
The patent applies local quality by varying the motor coil arrangement specifically in the curvilinear section rather than the entire track. The motor coils are angled relative to the track centerline by an angle θ that varies with the local radius of curvature, allowing the system to adapt to curved sections while maintaining simple straight-section configurations.
Solution Approach 2:
The patent changes the parameter of motor coil orientation angle θ as a function of the local track radius of curvature. By adjusting this parameter dynamically across different track sections, the system achieves adaptability to curvilinear paths without requiring completely different motor designs for each section.
2Ease of operation
If conventional linear motor systems traverse curved track sections, then the system can change direction, but unwanted forces and jerk are produced affecting stability
Solution Approach 1:
The patent uses clothoid curve geometry to define the curvilinear track section, where the radius of curvature changes gradually rather than abruptly. This curved transition profile ensures that the motor coil angle θ changes smoothly, producing sinusoidal acceleration profiles that minimize jerk and maintain moving element stability during direction changes.
3Measurement precision
If conventional linear motor systems use standard tracking methods, then the tracking system is simple, but tracking accuracy deteriorates on curvilinear sections
Solution Approach 1:
The patent replaces mechanical position sensing with optical sensors that detect the position of the moving element relative to the curvilinear track. The control system uses the known clothoid geometry and motor coil angle relationships to calculate accurate position feedback, achieving high tracking precision without complex mechanical encoders.
4Adaptability or versatility
If conventional linear motor systems transition between straight and curved sections, then the system can handle complex paths, but alignment and configuration become difficult
Solution Approach 1:
The patent divides the track into distinct modular sections: straight sections with standard motor coil arrangements and curvilinear sections with angled motor coils. Each section can be manufactured and aligned independently, with the transition zones using clothoid geometry to ensure smooth connections. This segmentation simplifies manufacturing and alignment while maintaining path flexibility.
Data Source
AI summary
A curvilinear track section of a linear motor system for use with a moving element including a machine readable medium, the track section including: a curvilinear track portion having a predetermined curved shape; a plurality of sensors provided to the track portion such that each of the plurality of sensors is oriented perpendicular to the direction of motion while the plurality of sensors are placed along the direction of motion and the plurality of sensors are configured such that the machine readable medium will overlap at least two of the plurality of sensors at the same time; and a processor configured to determine a position of the moving element on the curvilinear track section based on the readings from the sensors.