Active Hydraulic Ripple Cancellation via Stabilized Pump Control
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Solution Overview
Problem
Hydraulic systems employing positive displacement pumps suffer from flow ripple, which leads to oscillations in operating pressure, potentially causing equipment failure and degrading customer experience.
Innovation Solution
The implementation of a pressure-balanced active buffer and a method for operating a positive displacement pump, involving the detection of pump position, accessing a ripple map, determining a stabilized command profile, and operating an active component according to this profile to attenuate flow ripple.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a positive displacement pump operates at constant speed, then the pump maintains stable operating conditions, but flow ripple and pressure oscillations occur
Solution Approach 1:
The patent applies periodic action by modulating the pump speed according to a predetermined speed profile that varies periodically. The controller adjusts the rotational speed of the pump in a periodic manner to counteract the flow ripple generated during constant speed operation, thereby reducing pressure oscillations while maintaining stable operating conditions
Solution Approach 2:
The patent implements parameter changes by varying the rotational speed parameter of the pump according to a predetermined speed profile. Instead of maintaining constant speed, the controller dynamically adjusts the speed parameter to compensate for flow ripple, transforming the operating parameters to achieve reduced pressure oscillations
2Object-generated harmful factors
If pump speed is varied to reduce flow ripple, then pressure oscillations are attenuated, but control complexity increases
Solution Approach 1:
The patent applies preliminary action by establishing a predetermined speed profile before operation. The controller uses this pre-defined profile to adjust the pump speed in advance according to the anticipated flow ripple pattern, simplifying the control process by avoiding complex real-time calculations while effectively attenuating pressure oscillations
Data Source
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AI summary
Presented herein are systems and methods for attenuating flow ripple generated by a hydraulic pump. In certain aspects, a method and system for operating a hydraulic positive displacement pump according to a stabilized command profile are disclosed, such that flow ripple generated by operation of the pump according to the stabilized command profile is attenuated as compared to operation of the pump according to a corresponding nominal command profile. In other aspects, a pressure-balanced active buffer is disclosed that allow for at least partially cancelling flow ripple in a hydraulic circuit comprising a pump. In another aspect, a method for generating ripple maps for a pump is disclosed. Such ripple maps may be used, for example, to determine the stabilized command profile used to operate the pump, or may be used by the pressure-balanced active buffer to counteract ripple in the hydraulic circuit.