Compressor Pressure Measurement via Motor Speed
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Solution Overview
Problem
Existing electronically supported breakdown assistance devices for vehicle tires face high production costs and reduced reliability due to the need for electronic pressure sensors, which are expensive and sensitive to high temperatures at compressor outlets.
Innovation Solution
The method determines the change in electric motor speed, which is proportional to compressor outlet pressure, eliminating the need for separate pressure sensors by using a speed sensor, preferably non-contact inductive, to provide a pressure-proportional input variable for the control device, allowing for cost-effective pressure measurement and control without additional sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electronic pressure sensors are used to measure compressor outlet pressure, then pressure control precision is improved, but production costs increase and reliability decreases due to high temperature sensitivity
Solution Approach 1:
The patent replaces the mechanical/electronic pressure sensor system with an electrical measurement system. Instead of directly measuring pressure with a sensor exposed to high temperatures, the system measures electrical parameters (current, voltage, frequency) of the motor driving the compressor, which are indirectly related to pressure through the mechanical load. This substitution eliminates the reliability issues of pressure sensors in high-temperature environments while maintaining sufficient measurement precision for control purposes.
Solution Approach 2:
The patent introduces an intermediary measurement approach by using motor electrical parameters as a mediator to infer compressor outlet pressure. Rather than placing a sensor directly in the high-temperature pressure environment, the system uses the motor's electrical characteristics (which are easier to measure and less sensitive to temperature) as an intermediate indicator that correlates with the actual pressure condition, thereby solving both precision and reliability concerns.
2Extent of automation
If electronic pressure sensors are installed at compressor outlet to enable pressure control, then control accuracy is improved, but production costs increase significantly
Solution Approach 1:
The patent replaces expensive electronic pressure sensing hardware with cheaper electrical measurement systems. By measuring motor current, voltage, and frequency—parameters already present in the motor control circuitry—the system achieves automated pressure control without requiring additional costly pressure sensors, thereby maintaining control automation while significantly reducing production costs.
Solution Approach 2:
The patent enables the motor control system to serve dual purposes: controlling motor operation and indirectly measuring compressor pressure. The existing motor control electronics perform self-service by utilizing their own measurement capabilities (electrical parameters) to infer pressure conditions, eliminating the need for separate, expensive pressure sensing hardware and simplifying the overall system manufacturing.
3Measurement precision
If pressure sensors are exposed to high temperature at compressor outlet, then pressure measurement is enabled, but service life of the sensor decreases
Solution Approach 1:
The patent substitutes the vulnerable pressure sensor with a robust electrical measurement system. By measuring motor electrical parameters that reflect pressure conditions without requiring physical exposure to the high-temperature compressor outlet environment, the system maintains pressure measurement capability while dramatically extending the service life of the measurement components, as electrical sensors are not subjected to thermal degradation.
Solution Approach 2:
The patent uses motor electrical parameters as an intermediary that allows pressure inference without direct exposure to harsh conditions. The electrical measurements are taken from the motor, which operates in a cooler, more accessible environment compared to the compressor outlet. This intermediary approach preserves measurement capability while protecting the measurement system from thermal damage, thereby extending service life.
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 approach reduces production costs and increases the service life and reliability of small compressors by using speed sensors that are cheaper, easier to integrate, and less thermally loaded, enabling accurate pressure control without additional mechanical pressure limitation.
Implementation Method 1
using a speed sensor, preferably non-contact inductive, to provide a pressure-proportional input variable for the control device
Data Source
Figure 1~2
Figure 3~4
AI summary
Method for measuring the pressure generated by a compressor driven by an electric motor, preferably a reciprocating compressor (3) driven by an electric motor via a slider crank mechanism; in said method, the change in the speed of the electric motor (2) driving the compressor is determined, and said change in speed, which is dependent on the pressure variation at the compressor outlet, is supplied to a control device or control unit (4) or displayed as a pressure-proportionate input variable for operating the compressor.