Electronically Commutated Hydraulic Machines for Multi-Rotor Aerial Vehicles
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Solution Overview
Problem
Conventional hydraulic systems in multi-rotor aerial vehicles suffer from poor energy efficiency, inaccurate control, and mechanical complexity, which limits their ability to maintain stable flight and payload capacity due to issues with proportional valves, swashplate pumps, and the need for multiple independent pumps.
Innovation Solution
The use of electronically commutated hydraulic machines with phased control of working chambers and electronically controllable valves allows for independent control of rotor speeds, reducing energy losses and mechanical complexity while enhancing control accuracy and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional proportional valves are used to control hydraulic motors, then the system can deliver high power density, but energy efficiency deteriorates due to throttling losses
Solution Approach 1:
The patent replaces conventional mechanical proportional valves with an electronically commutated hydraulic machine that uses electronic control to regulate hydraulic fluid flow. This substitution eliminates the throttling mechanism inherent in proportional valves, replacing it with electronic switching control that directs hydraulic fluid to working chambers in phases, thereby eliminating throttling losses while maintaining high power density
Solution Approach 2:
The patent changes the control parameter from continuous throttling control to discrete electronic commutation control. By controlling the timing and sequencing of hydraulic fluid delivery to working chambers through electronic signals, the system achieves precise control without the energy-wasting throttling effect, thus improving energy efficiency while maintaining power output
2Device complexity
If conventional proportional valves are used, then the system can be simple in structure, but control accuracy deteriorates due to hysteresis and non-linearity
Solution Approach 1:
The patent replaces mechanical proportional valves with an electronically commutated hydraulic machine that uses electronic control signals to regulate hydraulic fluid flow. This substitution eliminates the hysteresis and non-linearity inherent in mechanical valve systems, providing precise and linear control response that significantly improves control accuracy while maintaining manageable system complexity
Solution Approach 2:
The patent incorporates feedback control mechanisms where the controller monitors the actual position and speed of the hydraulic machine and adjusts the electronic commutation signals accordingly. This feedback loop compensates for any deviations and ensures high control accuracy by continuously correcting the hydraulic fluid delivery timing and amount
3Speed
If conventional proportional valves are used, then the system can respond to control inputs, but response speed deteriorates due to phase lag
Solution Approach 1:
The patent replaces mechanical proportional valves with an electronically commutated hydraulic machine that responds to electronic control signals. This substitution eliminates the mechanical inertia and damping effects of proportional valves, enabling the system to respond much faster to control inputs with minimal phase lag, thereby improving response speed and reducing control delay
Solution Approach 2:
The patent uses periodic electronic commutation signals to control the hydraulic fluid delivery to working chambers. By synchronizing the hydraulic fluid delivery with the rotational position of the hydraulic machine through phased electronic control, the system achieves rapid and precise response to control inputs, eliminating the delayed response characteristic of conventional proportional valve systems
4Ease of operation
If multiple independent pumps are used to drive hydraulic motors, then each motor can be controlled independently, but device complexity increases
Solution Approach 1:
The patent merges multiple hydraulic pump functions into a single electronically commutated hydraulic machine. By using electronic control to selectively direct hydraulic fluid to different working chambers at different phases, the system achieves independent control of multiple hydraulic motors while using only one pump, thereby reducing mechanical complexity while maintaining independent control capability
Solution Approach 2:
The electronically commutated hydraulic machine performs multiple functions: it acts as a single pump that can simultaneously or sequentially supply hydraulic fluid to multiple different working chambers and ultimately multiple hydraulic motors. This multi-functionality eliminates the need for multiple separate pumps while maintaining the ability to independently control each motor, significantly reducing system complexity
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
This solution provides improved control accuracy, response time, and energy efficiency, enabling multi-rotor aerial vehicles to maintain stable flight and increased payload capacity with reduced weight and mechanical complexity.
Implementation Method 1
the displacement of hydraulic fluid through each working chamber is regulated by one or more electronically controllable valves, during each cycle of working chamber volume, in phased relationship to cycles of working chamber volume, to thereby regulate the net displacement of hydraulic fluid through the fluid outlets or inlets
Data Source
AI summary
A multi-rotor aerial vehicle comprises at least two rotors, a controller, a power supply having an output shaft, a shaft-driven hydraulic machine coupled to the output shaft and at least two rotor-driving hydraulic machines coupled to respective rotors. At least one of the hydraulic machines is an electronically commutated hydraulic machine in which displacement of hydraulic fluid through each working chamber is regulated by electronically controllable valves, during each cycle of working chamber volume, in phased relationship to cycles of working chamber volume. The controller controls the electronically controllable valves of the electronically commutated hydraulic machines to independently control the rotation of the rotors. The shaft-driven hydraulic machine may be an electronically commutated machine with a plurality of independent outputs, which independently drive the rotor-driving hydraulic machines. The rotor-driving hydraulic machines may be electronically commutated machines the displacement of which is independently controlled to independently drive the rotors.