Object Detection Apparatus Dynamic Code Sequence Length Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing object detection apparatuses installed on moving bodies, such as vehicles, struggle to adjust the range of relative speed of detected objects according to the speed of the moving body, leading to inconsistent detection performance across varying speed conditions.
Innovation Solution
An object detection apparatus that includes a transmission signal generator, modulation unit, wave transmission and reception unit, pulse compression unit, and movement speed acquisition unit, which adjusts the length of the code sequence based on the moving body's speed to modify the relative speed range of detected objects, improving signal-to-noise ratio and detection range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the code sequence length is fixed, then the device complexity is reduced, but the adaptability to different speed conditions deteriorates
Solution Approach 1:
The code sequence length is made dynamically adjustable based on the moving body's speed. The system switches between a first code sequence length (when speed ≥ first threshold) and a second code sequence length (when speed < first threshold), enabling adaptation to different speed conditions while maintaining manageable device complexity through controlled variability.
2Reliability
If the code sequence length is increased, then the signal-to-noise ratio is improved, but the detection range for slow-moving objects deteriorates
Solution Approach 1:
Different code sequence lengths are applied locally according to the operating conditions. When the moving body travels at high speed, a longer code sequence length is used to improve S/N ratio. When traveling at low speed, a shorter code sequence length is used to maintain detection capability for slow-moving objects. This local optimization resolves the contradiction between S/N ratio improvement and detection range preservation.
3Adaptability or versatility
If the code sequence length is decreased, then the detection range for slow-moving objects is improved, but the signal-to-noise ratio deteriorates
Solution Approach 1:
The system changes the parameter of code sequence length based on the moving body's speed. By switching between different code sequence length values according to speed conditions, the system optimizes both S/N ratio and detection range for slow-moving objects, resolving the contradiction between these two performance aspects.
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
The apparatus effectively extends the object detection range and improves the signal-to-noise ratio by dynamically adjusting the code sequence length in response to the moving body's speed, enabling accurate detection of objects across a wide range of relative speeds, from high-speed travel to low-speed scenarios.
Implementation Method 1
a modulation signal of the transmission signal is generated by performing digital modulation on each of the multiple pulse sequences of the transmission signal according to a code sequence
Implementation Method 2
an object detection apparatus for detecting an object, or existence of an object, by transmitting a pulse signal and receiving a reflected signal reflected by an object
Implementation Method 3
correlation (i.e., auto-correlation) between the received signal and the modulation signal is calculated, and such calculation result is used to compress the pulse width of the received signal, for the improvement of the S/N ratio
Implementation Method 4
an object detection apparatus that uses a correction signal for correcting the Doppler shift of the received signal, which is received as a Doppler shifted signal from an object that moves at a constant speed
Data Source
AI summary
An object detection apparatus disposed in a moving body generates a transmission signal of multiple pulse sequences as a plurality of sequences of multiple pulses. A modulation signal of the transmission signal is generated by performing digital modulation on each of the multiple pulse sequences of the transmission signal according to a code sequence. A transmission wave based on the modulation signal is transmitted and a reflected wave of the transmission wave is received by the apparatus. The apparatus further detects a speed of the moving body to determine a length of the code sequence. The apparatus calculates a code correlation value between the modulation signal and a received signal, which is derived from the reflected wave, and performs pulse compression on the received signal based on the code correlation value to generate a pulse-compressed received signal. The apparatus detects an object based on the pulse-compressed received signal.