Spherical BLDC Machine for Compact Multi-DoF Motion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current motion control systems for multi-degree of freedom applications are large, cumbersome, and inefficient, making them unsuitable for small platforms like mini- or micro-UAVs and micro-satellites, and require complex manufacturing techniques.
Innovation Solution
A spherical brushless direct current (BLDC) machine with multiple stators and a spherical rotor, where each stator is symmetrically disposed about a different axis, and the rotor is moveable relative to the stators, utilizing multi-phase windings and a control system to manage current magnitudes and directions for precise movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate motors or actuators are used for each degree of freedom, then multi-DoF motion control is achieved, but the system becomes large and cumbersome
Solution Approach 1:
The patent combines multiple motors (first motor for pan rotation, second motor for tilt rotation, third motor for roll rotation) into a single integrated spherical mechanism. The spherical rotor serves as a common rotating element for all three motors, allowing multi-DoF motion control to be achieved within a compact volume rather than using separate actuators that would occupy more space.
Solution Approach 2:
The invention transitions from conventional linear/planar motor arrangements to a spherical geometry. By using spherical stators arranged at different orientations (first stator for pan, second stator for tilt, third stator for roll) around a spherical rotor, the system achieves multi-degree of freedom motion in three-dimensional space, enabling compact implementation of complex motion control.
2Adaptability or versatility
If multiple separate motors are used for multi-DoF motion, then motion control is achieved, but the system becomes cumbersome and inefficient
Solution Approach 1:
The patent merges multiple motor functions into a single integrated system where the spherical rotor is controlled by three motors working in coordination. This unified approach eliminates the need for separate mechanical linkages and control systems that would be required for multiple independent actuators, thereby improving overall system efficiency and reducing mechanical losses.
Solution Approach 2:
The spherical rotor serves multiple functions simultaneously - it is the rotating element for the first motor (pan), the second motor (tilt), and the third motor (roll). This multi-functional design allows a single component to perform what would otherwise require multiple separate actuators, improving efficiency by reducing redundant mechanical elements and control overhead.
3Volume of moving object
If conventional multi-axis machines are developed to address size issues, then system size is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent divides the compact spherical mechanism into distinct modular components: first stator with first motor, second stator with second motor, third stator with third motor, and the spherical rotor. Each stator-motor assembly can be manufactured and assembled separately, then integrated around the common spherical rotor. This segmentation allows for simplified manufacturing of individual components while achieving a compact overall system.
Solution Approach 2:
The invention uses spherical geometry for the rotor and arranges stators in spherical configurations, which simplifies the manufacturing of individual components compared to complex multi-axis mechanical linkages. The spherical shape allows for uniform distribution of magnetic fields and forces, enabling standard motor manufacturing techniques to be applied while achieving compact multi-DoF motion control.
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 spherical BLDC machine provides a compact, efficient, and less cumbersome solution for multi-degree of freedom motion control, enabling smaller and more efficient systems without the need for complex manufacturing, suitable for applications like UAVs and gimbal stabilization.
Implementation Method 1
a first multi-phase winding wound on the first stator core, a second multi-phase winding wound on the second stator core, and a third multi-phase winding wound on the third stator core
Implementation Method 2
The spherical rotor includes a plurality of magnets that emanate a magnetic field, and each magnet has at least one of its magnetic poles facing the first, second, and third stators
Data Source
AI summary
A spherical brushless direct current (BLDC) machine includes a first stator, a second stator, and a spherical rotor. The first stator is symmetrically disposed about a first axis and includes a first multi-pole stator core having a first multi-phase winding wound thereon. The second stator is symmetrically disposed about a second axis and includes a second multi-pole stator core having a second multi-phase winding wound thereon. The second stator core is coupled to the first stator core, and the second axis intersects the first axis. The spherical rotor is disposed adjacent to, and is moveable relative to, the first and second stators. The spherical rotor includes a plurality of magnets that emanate a magnetic field, and each magnet has at least one of its magnetic poles facing the first and second stators.