Direct-Drive Pole Array Actuator for High-Bandwidth Torque Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motor-driven actuators face limitations in dynamic bandwidth, torque, and precision due to gearing non-linearities, and direct drive actuators without gearboxes still lack sufficient bandwidth and control over instantaneous starting/stopping torque and slow speed precision.
Innovation Solution
A direct drive actuator system with multiple electromagnet pole arrays on both the rotor and stator, controlled by dedicated electronics and algorithms, generates electromagnetic forces for precise movement without contact, using high-resolution encoders and wireless communication for enhanced reliability and precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If traditional motor-driven actuators with gearboxes are used, then torque multiplication is achieved, but non-linearities (backlash, static friction, mechanical compliance) limit dynamic bandwidth and precision
Solution Approach 1:
The patent replaces the mechanical gearbox system with an electromagnetic direct-drive system. Multiple independently controlled electromagnet pole arrays generate electromagnetic forces that directly move the driven structure without mechanical transmission components, eliminating backlash, static friction, and mechanical compliance while maintaining sufficient torque output.
Solution Approach 2:
The actuator is divided into multiple independently controllable pole arrays (first plurality and second plurality) with individual windings. Each pole array can be selectively energized to generate precise electromagnetic forces, enabling fine control of the driven structure's motion and eliminating the non-linearities associated with single-point mechanical drives.
2Device complexity
If permanent magnet motors are used for direct drive, then gearbox elimination is achieved, but bandwidth, instantaneous starting/stopping torque, and slow speed precision remain insufficient
Solution Approach 1:
Instead of using a single permanent magnet motor, the patent employs multiple pole arrays with individually controllable windings. This segmentation allows independent control of each pole array, enabling precise generation of electromagnetic forces for high bandwidth operation, instantaneous torque changes, and accurate slow-speed positioning without the limitations of conventional permanent magnet motors.
Solution Approach 2:
The patent changes the control parameter from fixed permanent magnet fields to dynamically adjustable electromagnetic fields generated by individually controlled windings. This allows real-time modification of magnetic field strength and distribution, enabling precise control of instantaneous starting/stopping torque and high-speed response while maintaining direct drive simplicity.
3Device complexity
If single-point contact drive systems are used, then mechanical simplicity is maintained, but insufficient torque and stiffness prevent high bandwidth achievement
Solution Approach 1:
The drive system is segmented into multiple pole arrays distributed around the driven structure, with each array contributing to the total torque and stiffness. This distributed arrangement maintains mechanical simplicity by eliminating gearboxes while multiplying the effective torque and stiffness through coordinated activation of multiple electromagnetic poles, enabling high bandwidth operation.
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 system achieves higher bandwidth, accuracy, and reduced wear, providing significant advantages in disturbance-rejection performance and long-term reliability by eliminating the need for gearboxes and allowing precise control of electromagnetic forces.
Implementation Method 1
the controller is configured to selectively electrically energize windings of the first plurality of pole arrays and the second plurality of pole arrays such that an electro-magnetic force is formed between poles of the first plurality of pole arrays and poles of the second plurality of pole arrays
Data Source
AI summary
A direct drive drive actuator includes a base structure and a driven structure that is journally supported and translatable relative to the base structure. The driven structure is disposed in a fixed spatial relationship to the base structure. A plurality of first pole arrays is disposed on the driven structure. A plurality of second pole arrays, corresponding in number to the plurality of first pole arrays is disposed on the base structure. An electrical power source is provided. A controller is coupled to the power source and the first plurality of pole arrays and the second plurality of pole arrays, wherein the controller is configured to selectively electrically energized windings of the first plurality of pole arrays and the second plurality of pole arrays such that an electro-magnetic force is formed between poles of the first plurality of pole arrays and poles of the second plurality of pole arrays. The driven structure is translatable relative to the base structure responsive to the electro-magnetic force.