Ultrasonic Sensor Signal Evaluation Using Digital Logic Reference Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ultrasonic devices for vehicle surroundings detection using quadrature phase detection face challenges in simplifying signal evaluation and generating required reference signals, leading to potential phase errors and increased demands on analog-to-digital converters.
Innovation Solution
The method involves generating digitally shifted reference signals using digital logic operations, allowing for easier quadrature phase detection by mixing sensor signals with these reference signals, reducing sampling rate demands, and enabling flexible use without a fixed carrier frequency, thus avoiding 1/f noise and allowing for optimal data analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If quadrature phase detection is used to evaluate ultrasonic signals, then signal evaluation capability is improved, but phase errors occur due to dependence on resonance frequency accuracy
Solution Approach 1:
The patent replaces the conventional analog quadrature phase detection method with a digital signal processing approach. Instead of relying on analog phase-locked loops and resonance frequency matching, the system uses digital logic circuits to generate reference signals and performs mixing and detection entirely in the digital domain, eliminating phase errors caused by resonance frequency variations
Solution Approach 2:
The patent changes the fundamental parameter of how reference signals are generated - from analog resonance-based generation to digital logic-based generation. By using digital logic circuits to produce reference signals with precise phase relationships, the system achieves phase accuracy independent of the ultrasonic sensor's resonance frequency
2Measurement precision
If conventional quadrature phase detection is used, then signal evaluation is performed, but generation of required reference signals becomes complex
Solution Approach 1:
The patent substitutes complex analog reference signal generation circuits with simple digital logic circuits. The digital logic approach uses basic logic gates and flip-flops to generate the four reference signals at different phase shifts, dramatically simplifying the hardware implementation while maintaining the ability to perform quadrature phase detection
Solution Approach 2:
The patent creates digital copies of the reference signals through logic operations. Instead of generating four separate analog reference signals with precise phase shifts, the system generates a single digital base signal and creates four phase-shifted versions through digital logic, simplifying the generation process
3Measurement precision
If high sampling rate is used to maintain signal accuracy, then measurement precision is improved, but demands on analog-to-digital converter increase
Solution Approach 1:
The patent substitutes the requirement for high-speed analog-to-digital conversion with digital signal processing techniques. By performing the mixing and detection operations in the digital domain after initial low-rate sampling, the system achieves high measurement precision without requiring high-speed ADCs, reducing the demands on the analog-to-digital converter
4Ease of operation
If fixed carrier frequency is used in ultrasonic detection, then signal transmission is simplified, but 1/f noise is introduced
Solution Approach 1:
The patent introduces dynamic frequency adjustment capability to the ultrasonic detection system. Instead of using a fixed carrier frequency that introduces 1/f noise, the system can dynamically adjust the operating frequency, allowing it to avoid problematic frequency ranges while maintaining simplified signal transmission through the digital signal processing approach
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 eliminates phase errors, reduces data volume, and improves signal-to-noise ratio, enabling more extensive and accurate signal evaluation and analysis of ultrasonic sensor data.
Implementation Method 1
The sensor unit emits ultrasonic signals into an area to be monitored and, in response to the emitted ultrasonic signals, receives echo signals
Implementation Method 2
the received echo signals are mixed with digitally generated reference signals, so that no phase errors occur
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a method for evaluating signals (ULS) from a sensor unit with at least one ultrasonic sensor, wherein ultrasonic signals are emitted into an area to be monitored and echo signals (ULS) are received in response to the emitted ultrasonic signals and evaluated for the detection of objects and/or object movements in the area to be monitored, wherein the received echo signals (ULS) are subjected to quadrature phase detection for evaluation, as well as a device for environmental detection in a vehicle and a data processing program and a computer program product for carrying out the method.To simplify further signal evaluation by quadrature phase detection and to enable the simple generation of required reference signals for quadrature phase detection, reference signals (S1, S2, S3, S4) required for quadrature phase detection are generated from a digital basic signal (S0) using digital logic gates (12, 14, 16, 18), whereby four reference signals (S1, S2, S3, S4) each phase-shifted by 90° are generated and each is mixed individually with the received echo signals (ULS).