Pneumatic Cylinder Pressure Control Without Position Sensors
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Solution Overview
Problem
Existing methods for supplying compressed air to compressed air consumers, such as pneumatic cylinders, often require complex position measuring systems and indirect pressure-based control of valve arrangements, leading to inefficient energy use and potential wear due to oversizing of components.
Innovation Solution
The method involves independently controlling two valve arrangements based solely on supply pressure, working space pressures, and outlet pressure to create predeterminable fluid mass flow or pressure profiles, eliminating the need for position measuring systems and ensuring energy-efficient operation by adjusting fluid flows to match movement tasks precisely.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If position measuring systems are used to control valve arrangements, then movement control precision is improved, but device complexity increases
Solution Approach 1:
The patent extracts and eliminates the position measuring system from the control loop. Instead of measuring position and indirectly inferring flow conditions, the system directly measures pressure at the consumer and uses this pressure information to directly control the valve arrangement, achieving position control without complex position sensors.
Solution Approach 2:
The patent introduces pressure as an intermediary parameter that directly reflects the flow conditions at the consumer. By measuring pressure instead of position, and using pressure to control valve opening, the system creates a simpler feedback loop where pressure serves as both the measurement and control variable.
2Device complexity
If indirect pressure-based control is used, then device complexity is reduced, but energy efficiency deteriorates
Solution Approach 1:
The patent implements direct pressure feedback from the consumer to the valve control. The pressure sensor is positioned at the consumer, and this pressure signal directly influences valve opening, creating a closed-loop feedback system that automatically adjusts flow to match actual demand, preventing energy waste from oversized or continuous flow.
Solution Approach 2:
The system dynamically adjusts valve opening based on real-time pressure feedback. The valve arrangement can continuously modulate its opening degree in response to pressure changes, enabling the system to adapt flow rates to actual consumer needs rather than operating at fixed or oversized settings.
3Reliability
If oversized components are used, then reliability is improved, but energy consumption increases
Solution Approach 1:
The dynamic pressure-based control enables oversized components to operate at optimal points by continuously adjusting flow rates. When demand is low, the valve restricts flow to match actual needs; when demand is high, the valve opens fully. This prevents the energy waste that occurs with oversized components operating in a partially loaded state.
Solution Approach 2:
The system changes the operating parameters (flow rate, pressure) dynamically based on actual demand. By monitoring pressure and adjusting valve opening accordingly, the system ensures that even oversized components operate efficiently by matching their output to actual consumer requirements rather than running at constant high flow rates.
4Measurement precision
If complex position control systems are implemented, then movement precision is improved, but wear increases
Solution Approach 1:
The patent removes the complex position measuring and control mechanisms that cause wear. By using pressure as the control variable instead of position, the system eliminates the need for mechanical position sensors and complex control actuators, thereby reducing wear on moving parts while maintaining control precision through pressure-based flow regulation.
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 allows for precise control of fluid flows to achieve predetermined movement profiles, reducing energy consumption and preventing wear by ensuring the compressed air consumer operates within optimal parameters, even when oversized, and allows for smooth movement without complex measurement devices.
Implementation Method 1
each of the working chambers is assigned an independently controllable valve arrangement which can be set between a closed position, a first functional position for a fluidically communicating connection with a fluid source and a second functional position for a fluidically communicating connection with a fluid sink
Implementation Method 2
Changes in the valve position, depending on the pressure conditions at the compressed air consumer and a compressed air source, result in different fluid flow rates to the compressed air consumer. These changes are indirectly detected by the processing unit via the position signal
Data Source
Figure 1
AI summary
The invention relates to a method for the supply of compressed air to a compressed-air consumer (3) which has two fluidically separate, kinematically coupled working chambers (53, 54), wherein each of the working chambers (53, 54) is assigned an independently actuable valve arrangement which can be adjusted between a blocking position, a first functional position for a fluidically communicating connection to a fluid source (32), and a second functional position for a fluidically communicating connection to a fluid sink (33), and wherein each of the two valve arrangements is adjusted individually, in dependence on a predefinable movement objective for the compressed-air consumer (3) and in, preferably exclusive, dependence on at least two pressure values from the group: supply pressure, first working chamber pressure, second working chamber pressure, outlet pressure, for the provision of a predefinable profile for a fluid mass flow or for the provision of a predefinable profile for a fluid pressure in the respective working chamber or for the provision of a predefinable profile of a valve cross section.