Displacement Sensor Waveform Summation for Low Signal
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Solution Overview
Problem
In time-of-flight (TOF) displacement sensing, insufficient reflection signals due to object distance or surface reflectance lead to a decreased signal-to-noise ratio, making accurate measurements challenging.
Innovation Solution
A displacement sensor that includes an emitting unit, a receiving unit, a waveform summation unit, and a reception signal amount calculation unit, which generates a summation waveform by accumulating binary signals over time and calculates the reception signal amount based on waveform features, allowing for improved signal intensity measurement and adaptive adjustments to measurement parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the distance to the object increases or the surface reflectance decreases, then the measurement range is extended, but the signal-to-noise ratio decreases
Solution Approach 1:
The system performs preliminary actions by accumulating multiple temporal waveforms before making a measurement determination. The waveform summation unit accumulates binary signals over multiple periods, building up a sufficient signal level before the distance calculation unit processes the data, ensuring reliable measurement even at extended distances
Solution Approach 2:
The invention merges multiple temporal waveforms from different measurement periods into a single accumulated waveform. By combining multiple weak signals that fall below the threshold individually, the system creates a composite signal with sufficient amplitude for accurate distance calculation, effectively extending the measurement range while maintaining signal-to-noise ratio
2Measurement precision
If multiple temporal waveforms are accumulated to improve signal-to-noise ratio, then measurement accuracy is improved, but the measurement time increases
Solution Approach 1:
The system applies partial action by accumulating binary signals only for a predetermined number of periods rather than continuously. The waveform summation unit performs accumulation for a limited, predetermined number of cycles, achieving sufficient signal-to-noise ratio improvement without indefinite time extension, thus balancing accuracy with measurement speed
Solution Approach 2:
The accumulation process is performed as a preliminary step with a predetermined number of periods. By establishing the accumulation count in advance, the system prepares the signal to an adequate level before distance calculation begins, ensuring measurement accuracy is achieved within a predictable and controlled time frame
3Reliability
If the threshold value is set high to reduce noise influence, then measurement reliability is improved, but the detection sensitivity decreases
Solution Approach 1:
The invention merges multiple sub-threshold signals through waveform accumulation. Individual binary signals that fall below the threshold are combined over multiple periods, creating an accumulated waveform that exceeds the threshold while maintaining noise rejection. This allows the threshold to remain high for reliability while detecting weaker signals through cumulative effect
Solution Approach 2:
The system performs preliminary accumulation of signals before threshold comparison. By accumulating multiple temporal waveforms in advance, the system builds up signal amplitude so that even weak reflections eventually exceed the high threshold after sufficient accumulation periods, maintaining both reliability and detection sensitivity
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
Enables accurate displacement measurement and stable signal acquisition by calculating the reception signal amount and adjusting sensor parameters, enhancing measurement resolution and stability.
Implementation Method 1
a displacement is calculated on the basis of a time difference between emission of the pulse signal and reception of the reflection signal
Data Source
AI summary
A displacement sensor includes an emitting unit periodically emitting pulse signals; a receiving unit receiving reflection signals generated from the pulse signals and reflected by an object and outputs binary signals that indicate signal intensity of the received reflection signals; a waveform summation unit generating a summation waveform by accumulating temporal waveforms of the binary signals for the respective corresponding periods of time with reference to emission timings of the corresponding pulse signals; a distance calculation unit calculating a value that indicates a distance to the object on the basis of waveform features corresponding to waveform features of the pulse signals that appear in the summation waveform; and a reception signal amount calculation unit calculating a reception signal amount that is intensity of the reflection signals received by the receiving unit on the basis of feature amounts indicated by cumulative values that appear in the summation waveform.