Ultrasonic Object Detection Variable Gain Amplifier
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Solution Overview
Problem
Vehicular ultrasound devices face interference from harmonic noise and signal attenuation, leading to false alarms and misrecognition of objects due to environmental factors like remote walls and air temperature layers, which existing technologies struggle to address effectively.
Innovation Solution
An object detection apparatus and method that employs a variable gain amplifier, controlled by a gain controller using a linearly interpolated gain curve, to differentiate between object reflections and ambient noise, and calculates the object's position based on the maximum of the first-order differential value of the signal envelope.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a high gain amplifier is used to detect objects at short distances, then detection sensitivity is improved, but false alarms from remote walls and environmental noise increase
Solution Approach 1:
The patent applies dynamic gain control by adjusting the amplifier gain based on the time of flight of the ultrasonic signal. The gain is varied according to a pre-stored gain curve that corresponds to different time zones, allowing high gain for short distance detection while automatically reducing gain for long distance signals to prevent false alarms from remote walls.
Solution Approach 2:
The patent changes the gain parameter dynamically based on the time of flight. By storing multiple gain values corresponding to different time zones and selecting the appropriate gain based on the signal's time of flight, the system optimizes detection sensitivity for each distance range while suppressing environmental noise and false alarms.
2Measurement precision
If a high gain amplifier is used to detect objects at short distances, then signal detection capability is improved, but interference from air temperature layers and exhaust gas increases
Solution Approach 1:
The system dynamically adjusts the amplifier gain based on the time of flight to minimize the impact of environmental interference. By reducing gain for signals returning from long distances (where air temperature layers and exhaust gas cause false reflections), the system suppresses these harmful effects while maintaining high sensitivity for nearby objects.
Solution Approach 2:
The patent performs preliminary action by pre-storing gain curves and gain values corresponding to different time zones before actual object detection. This pre-prepared gain configuration allows the system to quickly select the appropriate gain level based on the signal's time of flight, effectively preventing environmental interference from affecting detection accuracy.
3Reliability
If two sensing processes are used to reduce false alarms, then reliability is improved, but detection speed and productivity decrease
Solution Approach 1:
The patent implements dynamic gain control within a single sensing process, eliminating the need for multiple sequential sensing operations. By adjusting the gain based on the time of flight of each detected signal, the system achieves both false alarm reduction and maintained detection speed, improving productivity while ensuring reliability.
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 enhances robustness against environmental interference, reduces false alarms, and simplifies the system structure while maintaining accurate object detection, even in complex environments.
Implementation Method 1
a transducer converts an electric signal generated by a pulse generation device into ultrasonic waves and transmits the ultrasonic waves, and the ultrasonic waves transmitted by the transducer are reflected by a surface of an object and then converted back by the transducer into an electric signal
Implementation Method 2
An object detection apparatus includes: an amplifier configured to amplify a reflected ultrasonic wave signal with a variable gain
Implementation Method 3
the ultrasonic waves transmitted by the transducer are reflected by a surface of an object
Data Source
AI summary
Provided are an object detection apparatus and method. The object detection apparatus includes an amplifier configured to amplify a reflected ultrasonic wave signal with a variable gain, a gain controller configured to set the variable gain such that the reflected ultrasonic wave signal received in at least one predetermined time zone is amplified with a high gain, compared to in other time zones, a comparator configured to compare a signal on an envelope corresponding to the signal amplified by the amplifier with a predetermined threshold and output the signal on the envelope when the signal is greater than the threshold, a calculator configured to calculate an absolute value of a first-order differential value of the signal on the envelope, and a time at which a maximum of the absolute value of the first-order differential value is calculated, and a detector configured to detect an object using a third time, the third time being a time at which the maximum is calculated, before a second time, the second time being a time at which the signal greater than the threshold is output.