Frequency Modulated Distance Detection Device
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Solution Overview
Problem
Conventional distance detection methods using pulse width modulation are limited by the number of pulse width modulation pins on microprocessors, requiring high clock frequencies and restricting precision due to hardware constraints, especially in devices like two-wheel robots.
Innovation Solution
A distance detection method and device that change the frequency of a directional signal and decode reflected signals to determine distance, eliminating the need for pulse width modulation and reducing hardware requirements by using a microprocessor with a directional signal emitting and receiving module with a constant bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pulse width modulation method is used for distance detection, then distance detection can be performed, but the microprocessor requires high clock frequency and has limited precision due to hardware constraints
Solution Approach 1:
The patent changes the modulation parameter from pulse width (duty cycle) to frequency. Instead of varying the duty cycle of PWM signals, the invention varies the frequency of the emitted infrared signal. The receiver detects the frequency of the reflected signal, and distance is determined based on the frequency shift. This parameter change eliminates the need for high-speed PWM generation and allows precise distance measurement with ordinary microprocessors.
2Adaptability or versatility
If pulse width modulation pins are used on microprocessor, then distance detection is enabled, but the number of available pins is limited especially in devices like two-wheel robots
Solution Approach 1:
The patent makes the microprocessor's general-purpose I/O pins capable of performing frequency modulation and frequency detection functions. By using software to generate frequency-modulated signals and software to detect frequencies, the same pins can serve multiple functions including distance detection, motor control, and other operations. This eliminates the need for dedicated PWM pins and increases system adaptability.
3Measurement precision
If infrared input/output pins with fixed duty cycle options are used, then distance detection can be performed, but the distance detection precision is very low due to limited duty cycle options
Solution Approach 1:
The patent changes the modulation parameter from pulse width (duty cycle) to frequency. Instead of varying the duty cycle of PWM signals, the invention varies the frequency of the emitted infrared signal. The receiver detects the frequency of the reflected signal, and distance is determined based on the frequency shift. This parameter change eliminates the need for high-speed PWM generation and allows precise distance measurement with ordinary microprocessors.
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 more precise distance detection without the limitations of pulse width modulation, requiring lower hardware capabilities and easier software implementation, enabling effective distance measurement across varying frequencies.
Implementation Method 1
judging whether the directional signal receiving module can decode a reflected directional signal into a received signal
Data Source
AI summary
Distance detection method and device are provided. The distance detection method comprises: providing a directional signal emitting module; providing a directional signal receiving module having a constant bandwidth; providing a distance detection signal to the directional signal emitting module; changing a frequency of the distance detection signal provided to the directional signal emitting module, and judging whether the directional signal receiving module can decode a reflected directional signal into a received signal; and judging a distance between an external object and the directional signal receiving module according to whether the received signal corresponding to the frequency of the distance detection signal can be decoded.