Lidar Transceiver Motion Actuation for Internal Reflection Disambiguation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lidar systems face challenges in distinguishing reflections from closely positioned objects from internal reflections, which can lead to inaccurate velocity and distance measurements due to the lack of Doppler shift in internal reflections.
Innovation Solution
The implementation of a lidar transceiver with a support platform that imparts a longitudinal velocity to the lidar transmitter and receiver, causing reflections from close objects to have a nonzero Doppler shift, thereby differentiating them from internal reflections with zero Doppler shift, using techniques such as rotating the lidar transceiver with an off-axis positioning or oscillating it along the direction of the transmitted beam.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If lidar systems use standard detection methods, then they can detect objects in the environment, but they cannot distinguish reflections from closely positioned objects from internal reflections
Solution Approach 1:
The patent applies the Dynamics principle by imparting a longitudinal velocity to the lidar transceiver itself through the support platform. This dynamic motion of the transceiver creates a Doppler shift reference frame that allows differentiation between internal reflections (which maintain zero Doppler shift relative to the transceiver) and external object reflections (which exhibit nonzero Doppler shift). This resolves the contradiction by enabling velocity measurement precision while preserving the ability to distinguish internal reflections from real objects.
Solution Approach 2:
The patent employs the Parameter changes principle by modifying the operational state of the lidar transceiver through the support platform's velocity impartment. By changing the transceiver's longitudinal velocity parameter, the system creates a measurable Doppler shift difference between internal and external reflections. This parameter change enables the system to maintain both measurement precision and the ability to distinguish reflection sources.
2Reliability
If the lidar transceiver is made stationary, then the device complexity is reduced, but the ability to distinguish close objects from internal reflections is lost
Solution Approach 1:
The patent applies the Dynamics principle by introducing controlled motion through the support platform to enable reliable object identification. The support platform provides the necessary longitudinal velocity to the transceiver, creating a dynamic system that can distinguish internal reflections from real objects through Doppler shift measurements. This dynamic approach maintains high reliability while managing device complexity through a dedicated support platform architecture.
Solution Approach 2:
The patent employs the Intermediary (Mediator) principle by introducing the support platform as an intermediary component between the transceiver and its mounting structure. This intermediary platform provides the necessary longitudinal motion to the transceiver without requiring complex integration of motion mechanisms directly into the transceiver itself. The support platform mediates the complexity by separating the motion generation function from the detection function, thereby maintaining reliability while managing overall device complexity.
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 the ability to accurately identify close objects, improving the safety and precision of autonomous vehicles and other applications by distinguishing real object reflections from internal artifacts, leading to better perception systems and driving decisions.
Implementation Method 1
Coherent rangefinders, which utilize the Doppler effect, can determine a longitudinal (radial) component of the object's velocity by detecting a change in the frequency of the returned wave from the frequency of the emitted signal.
Implementation Method 2
The implementation of a lidar transceiver with a support platform that imparts a longitudinal velocity to the lidar transmitter and receiver, causing reflections from close objects to have a nonzero Doppler shift
Data Source
AI summary
The disclosed aspects and implementations enable efficient disambiguation of spurious internal reflections in sensing (lidar, radar, or sonar) devices from reflections off closely positioned objects by imparting a longitudinal motion to the sensing devices, or components of such devices. In one implementation, the disclosed techniques involve outputting a transmitted wave and receiving a reflected wave generated by the transmitted wave while imparting, to a transceiver, a velocity along a direction of the transmitted wave. The techniques further involve detecting a difference of a transmitted wave frequency and a reflected wave frequency and determining whether the reflected beam is reflected from a real object located in an outside environment or is caused by an internal reflection within the sensing device.