Adaptive Pump Controller for Constant Damping
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Solution Overview
Problem
Conventional variable displacement transmission pumps face challenges in maintaining robust control stability and constant outlet pressure across varying operating conditions, especially in modern passenger car automatic transmissions with wide pressure spreads and small delivery quantities, leading to significant controller deviation and hysteresis.
Innovation Solution
A pump system with a controller that adjusts actuator actuators via a control valve to maintain constant damping of the control system, using equations for controller amplification based on system pressure, rotational speed, and load capacity to ensure stable operation across different operating points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a constant controller gain is used for the critical operating point, then control stability is improved at that specific point, but controller deviation and hysteresis increase significantly at non-critical operating points
Solution Approach 1:
The controller gain is made dynamically adjustable based on the operating point of the pump system. The control device determines the current operating point and adapts the controller gain accordingly, transitioning from a static constant gain to a dynamic variable gain that optimizes performance across all operating conditions, not just the critical point.
Solution Approach 2:
The controller gain parameter is changed adaptively based on operating conditions. By monitoring system parameters such as pressure and flow rate, the control device adjusts the controller gain to maintain optimal control stability and minimize deviation across the entire operating range, rather than using a fixed parameter value.
2Loss of energy
If the pump is designed for wide pressure spreads and small delivery quantities to reduce power consumption, then energy efficiency is improved, but control stability becomes more difficult to maintain
Solution Approach 1:
The control device continuously monitors the actual operating point and compares it with the optimal operating point. Based on this feedback, the controller adaptively adjusts the controller gain to maintain stable control performance across wide pressure spreads and small delivery quantities, enabling the pump to operate efficiently while maintaining reliability.
Solution Approach 2:
The control system introduces dynamic adaptability to handle the challenging operating conditions of wide pressure spreads and small delivery quantities. By making the controller gain variable rather than fixed, the system can maintain control stability across the extended operating range required for energy-efficient operation.
3Ease of manufacture
If the force difference on the differential piston is set permanently prior to installation, then the control system is simple to manufacture, but it cannot adapt to different operating points leading to poor control performance
Solution Approach 1:
The permanently set mechanical force difference on the differential piston is replaced by an electronically controlled adaptive system. The control device uses electronic signals to adjust the controller gain based on the operating point, eliminating the need for permanent mechanical adjustments while maintaining simplicity through electronic control rather than complex mechanical mechanisms.
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 stable and constant damping of the control loop, maintaining robust control stability and consistent pump outlet pressure by adaptively varying controller amplification according to system conditions, thereby improving efficiency and reliability.
Implementation Method 1
the pump delivery rate is influenced in such a way that only the volume flow actually required by the consumer is delivered. The pressure control is implemented by hydraulic-mechanical means, a force difference acting on a differential piston being used as an input variable.
Data Source
AI summary
A variable displacement transmission pump having a controller for adjusting the displaced volume, which controller actuates corresponding adjuster actuators of the adjustable pump via a control valve, so that the pump can be adjusted from minimum to maximum displaced volume in order to achieve a constant pump outlet pressure for supplying a hydraulically operated transmission, wherein for different operating points of both the adjustable pump and the transmission, the input variables of the controller are adjusted in such a way that, independently of the individual operating points, the overall damping of the control system comprising pump and transmission—that is, using corresponding influence variables from these systems—can be maintained substantially constant under variable operating conditions by means of adjustable controller amplification.