A radar angle calibration system is provided according to the present disclosure, including a radar simulator, a receiving horn antenna, a transmitting horn antenna, a turntable, and a controller. The radar is arranged on the turntable, and the radar rotates along with the turntable. The controller is configured to gradually change angle of transmitting the signals with a preset angle step by the turntable to obtain spatial responses of the receiving antenna array corresponding to signal sources in different DoAs, and obtain a spatial response matrix of the receiving antenna array according to the spatial responses corresponding to the signal sources in different DoAs.

Apparatus and methods are provided for using a retroflected target for calibrating environmental geometric sensing systems. In particular, apparatus and methods are provided for unstructured calibrations using a plurality of spatial sensing data acquisitions and the data correlations thereof. In various implementations, a combined LiDAR-RADAR detector is used to associate one with the other. According to one aspect of the present disclosure, a predetermined LiDAR detector is used as a reference frame for RADAR segmentation. Specifically, a LiDAR point-of-interest is conveyed to RADAR system for unstructured calibration. To that end, RADAR and LiDAR can be calibrated with one another without the need for absolute positioning.

An apparatus (1) for calibrating an ADAS sensor of an advanced driver assistance system of a vehicle (9), comprises: a base unit (2); a support structure (3) connected to the base unit (2); a vehicle calibration assistance structure (4), including a first surface which has a first combination of predetermined graphical features and which can be associated with the support structure so that the first surface, at an operating position, faces towards the service area (8); a flexible panel roller assembly connected to the support structure and including a roller and a flexible target panel (40).

An extrinsic-calibration system includes at least one target and a computer. Each target includes three flat surfaces that are mutually nonparallel and a corner at which the three surfaces intersect. The computer is programmed to estimate a first set of relative positions of the corner in a first coordinate frame from a first sensor, the first set of relative positions corresponding one-to-one to a set of absolute positions of the at least one target; estimate a second set of relative positions of the corner in a second coordinate frame from a second sensor, the second set of relative positions corresponding one-to-one to the set of absolute positions; and estimate a rigid transformation between the first coordinate frame and the second coordinate frame based on the first set of relative positions and the second set of relative positions.

An object detection device includes a first sensor, a second sensor, a calculation range selector and an estimator. The first sensor outputs a radio frequency (RF) signal, receives a reflected RF signal reflected from an object, and obtains a first measurement value for the object based on a received reflected RF signal. The second sensor obtains a second measurement value for the object by sensing a physical characteristic from the object. The physical characteristic sensed by the second sensor is different from a characteristic of the object measured as the first measurement value obtained by the first sensor. The calculation range selector sets a first reference range based on the second measurement value. The first reference range represents a range of execution of a first calculation for detecting a position of the object using a first algorithm. The estimator performs the first calculation only on the first reference range using the first measurement value, and generates a first result value as a result of performing the first calculation. The first result value represents the position of the object.

A method may include receiving at least one camera frame of a first radar target and a second radar target, determining an estimated radar pose based at least in part on the at least one received camera frame, receiving a first radar cross-section (RCS) response from the first radar target and second radar target, determining an estimated elevation angle based at least in part on the first RCS response, and determining an estimated radar angle by refining the estimated radar pose and the estimated elevation angle based on at least in part on the first RCS response.

A calibration apparatus and method suitable for calibration of an offset sensor of a subject vehicle. The calibration apparatus comprises a reference structure that is placed into, a reference locus using image data generated by a camera associated with the reference structure. An offset-target structure is then placed into position by coupling the offset-target structure to the reference structure, the coupling providing an appropriate locus for the offset-target structure during calibration of the offset sensor. The coupling restricts the linear and rotational displacement of the offset-target structure during calibration.

A method and a radar target simulator for generating a simulated radar echo signal. A radar signal is sent with known bandwidth from a radar sensor to be tested. The radar signal is received in the radar target simulator. The radar signal is filtered via a low-pass filter with known filter curve. The frequency spectrum of the filtered radar signal over the full bandwidth of the low-pass filter is determined. A corrected frequency spectrum and the power of a radar signal corresponding to the corrected frequency spectrum are calculated. A scaled radar signal from the filtered radar signal and the radar echo signal as a reflection of the scaled radar signal are calculated. The radar echo signal is sent from a transmitting antenna of the radar target simulator to the radar sensor to be tested.

Provided is a vehicle inspection system that enables inspection of an inspection vehicle provided with electromagnetic sensors having different wavelengths. A first absorption member and a second absorption member are provided to non-overlapping positions in front of a position at which the radiation range of radiated waves from the first electromagnetic sensor and the radiation range of radiated waves from the second electromagnetic sensor overlap.

Aspects and implementations of the present disclosure address shortcomings of existing technology by enabling autonomous vehicle simulations based on retro-reflection optical data. The subject matter of this specification can be implemented in, among other things, a method that involves initiating a simulation of an environment of an autonomous driving vehicle, the simulation including a plurality of simulated objects, each having an identification of a material type of the respective object. The method can further involve accessing simulated reflection data based on the plurality of simulated objects and retro-reflectivity data for the material types of the simulated objects, and determining, using an autonomous vehicle control system for the autonomous vehicle, a driving path relative to the simulated objects, the driving path based on the simulated reflection data.