Piezoelectric Force Measurement Device with Integrated Sensor-Actuator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing force-measuring devices suffer from measurement inaccuracies due to heat introduction from optical sensors and spatially offset sensors and actuators based on different principles, leading to non-linear relationships between external forces and deformation, and creep effects, which result in reduced precision and increased errors.
Innovation Solution
A force-measuring device where a piezo element acts as both sensor and actuator, integrated in a common assembly and aligned in the direction of the force, allowing for precise counteraction of deformation and reducing heat input, with the actuator and sensor sharing the same physical principle to react to external influences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an optical sensor is used to detect deformation, then the deformation can be measured, but heat is introduced which causes measurement errors
Solution Approach 1:
The patent replaces the optical sensor with a piezoelectric sensor that converts mechanical deformation directly into electrical signals. This substitution eliminates the optical measurement system that introduced heat, thereby removing the harmful thermal effect while maintaining deformation measurement capability through the piezoelectric effect.
Solution Approach 2:
The patent changes the measurement parameter from optical detection to piezoelectric signal generation. By utilizing the piezoelectric effect where mechanical stress directly produces electrical charge, the system achieves deformation measurement without the thermal interference inherent in optical systems.
2Adaptability or versatility
If optical sensor and piezoelectric actuator are arranged at different positions, then both can function independently, but measurement precision is reduced
Solution Approach 1:
The patent merges the sensor and actuator into a single integrated piezoelectric element that functions as both sensor and actuator. This unification ensures that the measurement point and actuation point coincide, eliminating spatial offset errors and improving measurement precision while maintaining full functionality through the reversible piezoelectric effect.
Solution Approach 2:
The piezoelectric element serves dual functions as both sensor and actuator. When an external force deforms the element, it generates an electrical signal for measurement. Conversely, when an electrical signal is applied, it produces mechanical displacement for actuation. This multi-functionality eliminates the need for separate components and their associated spatial offsets.
3Measurement precision
If deformation body is allowed to deform under external force, then the force can be measured, but non-linear relationships and creep effects reduce measurement accuracy
Solution Approach 1:
The patent implements a feedback control system where the piezoelectric sensor continuously monitors the deformation of the deformation body and feeds this information to a controller. The controller adjusts the piezoelectric actuator in real-time to counteract the deformation, maintaining the deformation body in its initial state. This active feedback compensates for non-linear effects and creep, ensuring accurate force measurement throughout the measurement range.
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 configuration enhances controllability, reduces measurement errors, and maintains linear relationships between external forces and measured variables, improving precision and accuracy by eliminating non-linearities and creep effects, and allowing for submicron deformation detection and counteraction.
Implementation Method 1
a sensor designed as a piezo element and an actuator which both act on the deformation body in the same way and which, in the direction of action, are arranged in layers in relation to one another
Implementation Method 2
one Actuator, which comprises a piezo element and which can be controlled by the control device as a function of the sensor signal in such a way that a restoring force can be exerted against the external force
Data Source
Figure 1~3
Figure 4
AI summary
The invention relates to a force measurement device comprising - a deformation body (10) supported on a base, which is in a zero position (12) when unaffected by external forces (13) and which can be deflected by an external force (13), and - a sensor (30) which comprises a piezo element and by means of which a signal dependent on the deformation of the deformation body (10) can be generated and transmitted to a control apparatus, wherein a measured value representative of the external force (13) can be determined by the control apparatus. The invention is characterized in that an actuator (31) which comprises a piezo element can be actuated by the control apparatus dependent on the sensor signal so that a restoring force can be exerted against the external force (13) on the deformation body (10), which can be thus transitioned back to the zero position (12) thereof.