Pulsating Measurement Averaging Using Dual-Filter Intersections
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Solution Overview
Problem
Current methods for averaging pulsating measurement quantities, such as those in 4-stroke engines and diaphragm pumps, rely on external features or fixed filter time constants, which are inadequate for precise regulation and often require additional sensors, leading to inefficiencies and phase lag in control systems.
Innovation Solution
A method involving time-discrete measurement values filtered with two different time constants, determining intersection points between signals to calculate the period and rotational speed of pulsating components, and forming arithmetic means between these points to derive accurate average values without external sensors, using a PT1 filter with optimized time constants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If external features or additional sensors are used for averaging pulsating measurement quantities, then the averaging can be performed, but the device complexity increases and phase lag occurs in control systems
Solution Approach 1:
The invention extracts the averaging function from external sensors and implements it within the existing electronic control device using software-based filtering. By processing the measurement quantity signal through filter algorithms with different time constants, the system achieves averaging without requiring additional hardware sensors, thus reducing device complexity while maintaining measurement precision.
Solution Approach 2:
The invention replaces the mechanical/physical approach of using external sensors and fixed filter hardware with an electronic/software-based filtering system. The control device uses computational filtering methods (exponential filtering with variable time constants) to perform averaging, substituting physical measurement hardware with electronic signal processing that reduces phase lag and improves responsiveness.
2Ease of manufacture
If fixed filter time constants are used for averaging, then the implementation is simple, but the phase lag increases and stability decreases
Solution Approach 1:
The invention transforms the static fixed filter time constant into a dynamic system that adapts to operating conditions. The electronic control device calculates optimal filter time constants based on the measured pulsation period and operational parameters, allowing the filtering characteristics to change dynamically. This ensures optimal averaging performance across different operating states while maintaining control stability and reducing phase lag.
Solution Approach 2:
The invention changes the filter time constant parameter from a fixed value to a variable that is calculated based on the measured pulsation period and operational conditions. By continuously adjusting the filter time constant parameter according to actual operating parameters, the system achieves both implementation simplicity and control reliability, avoiding the phase lag and stability issues associated with fixed filters.
3Measurement precision
If additional sensors are used to determine external features for averaging, then the averaging can be performed, but the quantity of components increases and cost increases
Solution Approach 1:
The invention makes the existing electronic control device perform multiple functions: it not only controls the system but also performs averaging of pulsating measurement quantities using its processing capabilities. By utilizing the control device's existing computational resources to implement the filtering and averaging algorithms, the system eliminates the need for separate averaging hardware or additional sensors, reducing the quantity of components while maintaining measurement precision.
Solution Approach 2:
The electronic control device serves itself by performing the averaging function internally without requiring external assistance from additional sensors or hardware. The control device uses its own processing capabilities to filter and average the measurement signals, making the system self-sufficient and reducing the overall component quantity and cost.
Data Source
AI summary
A method for averaging pulsating measurement quantities is disclosed. First, time-discrete measurement values (1) of the measurement quantity are recorded. Subsequently, first filtering of the measurement values (1) is carried out with a first filter time constant, during which a first signal (2) is obtained, and second filtering of the measurement values (1) with a second filter time constant, during which a second signal (3) is obtained, the second filter time constant being greater than the first filter time constant. Intersection points (4), at which the first signal (2) and the second signal (3) intersect, are then determined. Lastly, the arithmetic mean of the measurement values (1) between the intersection points (4) is taken.