Radar Device Radial Acceleration Estimation
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Solution Overview
Problem
Current radar devices are unable to accurately determine the acceleration of targets using radar waves, which is crucial for advanced driver assistance systems like automatic emergency braking and adaptive cruise control, as they primarily measure distance and relative velocity but lack the capability to assess acceleration effectively.
Innovation Solution
A method and radar device that utilize a two-dimensional Fourier transform to process radar signals, allowing for the determination of target distance, radial velocity, and acceleration by filtering out ghost targets and interfering reflections, and incorporating transverse velocity for precise acceleration estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If radar devices measure distance and relative velocity using conventional methods, then basic obstacle detection is achieved, but acceleration determination capability is lacking
Solution Approach 1:
The patent applies two-dimensional Fourier transform to process radar signals in both distance and velocity dimensions simultaneously, enabling acceleration extraction by analyzing the temporal evolution of velocity information. This dimensional transformation approach converts the acceleration measurement problem into a spectral analysis problem, resolving the contradiction between measurement capability and processing complexity.
Solution Approach 2:
The patent performs preliminary signal processing steps including two-dimensional Fourier transform and ghost target filtering before acceleration calculation. By preprocessing the radar signals to extract clean distance-velocity spectra and remove interfering reflections in advance, the system enables accurate acceleration determination without requiring overly complex real-time processing.
2Reliability
If radar devices process all target reflections to determine acceleration, then comprehensive acceleration data is obtained, but ghost targets and interfering reflections cause incorrect associations
Solution Approach 1:
The patent extracts and removes ghost targets and interfering reflections from the radar signal processing chain before acceleration calculation. By selectively filtering out false target reflections based on their characteristic patterns in the distance-velocity spectrum, the system isolates genuine target signals, thereby improving acceleration estimation reliability without requiring complex filtering algorithms.
Solution Approach 2:
The patent introduces the distance-velocity spectrum as an intermediary representation between raw radar signals and acceleration output. This intermediate spectral domain provides a clear distinction between genuine targets and ghost reflections, enabling reliable target selection and accurate acceleration determination through simplified filtering operations in the spectral domain.
3Measurement precision
If radar devices use additional measurements for angle and transverse velocity, then ghost targets are precluded and acceleration is optimized, but measurement complexity increases
Solution Approach 1:
The patent makes the radar system multi-functional by extracting multiple parameters (distance, velocity, angle, transverse velocity, and acceleration) from the same radar signal measurements. By processing the reflected signals to obtain both radial and transverse velocity components along with angular information, the system achieves comprehensive target characterization using a single radar device, eliminating the need for separate measurement systems.
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 solution enables the accurate estimation of target acceleration, enhancing safety features by distinguishing between deceleration and acceleration scenarios, thereby optimizing automatic emergency braking and adaptive cruise control functions.
Implementation Method 1
Radar sensors or radar devices may be used in different vehicles for locating obstacles or other vehicles
Implementation Method 2
The transmit signals are reflected by objects located in the transmission range. The reflected signals and/or received signals are recorded by a receiving device
Implementation Method 3
The evaluation unit converts the radar reception signals into digital measured values and is used for further processing of the digital measured values. In a further step, the digital measured values are subjected to a two-dimensional Fourier transform
Implementation Method 4
A relative velocity of objects may also be determined in addition to the distance of objects by the modulation of the transmit signals, for example, by FMCW (frequency modulated continuous wave) radar devices. In this case, frequency differences or delays result between the transmit signals and the received signals
Data Source
AI summary
A method is described for ascertaining an acceleration of a target or an object with the aid of radar waves. In a first step, at least one radar transmit signal is sent by at least one transmitting device. At least one radar reception signal reflected from a target is received and subsequently conveyed to an evaluation unit. The evaluation unit converts the radar reception signals into digital measuring values and is used for further processing of the digital measuring values. In a further step, the digital measuring values are subjected to a two-dimensional Fourier transform. At least one target reflection is detected on the basis of peak values or selected from a resulting absolute value spectrum or distance-velocity spectrum. At least one distance of a target from the transmitting device and at least one radial velocity of a target in relation to the transmitting device are ascertained based on the distance-velocity spectrum. Subsequently, at least one angle of the at least one target is determined in relation to an alignment of the transmitting device. Based on the determination or computation of the distance, the transverse velocity, and the angle, the particular signal components relevant for the estimation are separated. For at least one target reflection of an actual target or object, after carrying out an inverse Fourier transform, at least one radial acceleration is approximately computed from the remaining again transformed measured values. Furthermore, a radar device is described.