CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. § 371 as a U.S. National Stage Entry of International Application No. PCT/JP2018/031662, filed in the Japanese Patent Office as a Receiving Office on Aug. 28, 2018, which claims priority to Japanese Patent Application Number JP2017-173963, filed in the Japanese Patent Office on Sep. 11, 2017, each of which is hereby incorporated by reference herein in its entirety.

TECHNICAL FIELD

The present disclosure relates to a signal processing apparatus, a signal processing method, a program, and a moving body, and particularly, to a signal processing apparatus, a signal processing method, a program, and a moving body that can highly accurately estimate a self-position.

BACKGROUND ART

A technique of recognizing a situation of own surroundings to estimate a self-position is proposed to realize automatic drive.

For example, a technique is proposed, in which the distance to an object is calculated on the basis of an image using the time change of feature points or using an edge projector to thereby create an environment map (see PTL 1).

A technique is also proposed, in which a projector that periodically changes the luminance is used to extract reflected light synchronized with the change in the luminance to thereby detect reflecting objects and recognize the surroundings to estimate the self-position (see PTL 2).

CITATION LIST

Patent Literature

PTL 1: International Publication No. WO 2012/172870

PTL 2: JP 2016-197046A

SUMMARY OF INVENTION

Technical Problem

However, in the case of extracting the feature points from the image as in PTL 1, the accuracy of extracting the feature points may be reduced in a case where it is dark at night, and as a result, the accuracy of estimating the self-position may be reduced.

In addition, in the technique of PTL 1, the accuracy of extracting the feature points may be reduced if the image includes high-luminance saturated pixel regions, such as reflectors and glare from a light source.

Furthermore, in the case of PTL 2, if an oncoming car uses the same system, direct light from projectors of both cars may lead to misdetection.

The present disclosure has been made in view of the circumstances, and the present disclosure particularly improves estimation accuracy of a self-position.

Solution to Problem

An aspect of the present disclosure provides a signal processing apparatus including: a light projection unit that projects light at a predetermined wavelength; a light-receiving unit that takes an image of an object with a reflectance higher than a predetermined reflectance by receiving reflected light of the light projected by the light projection unit and reflected by the object; and an orientation estimation unit that estimates own orientation on the basis of the image taken by the light-receiving unit.

The signal processing apparatus can further include an object detection region extraction unit that obtains a difference image of an image in a state in which the light projection unit projects the light at the predetermined wavelength and an image in a state in which the light projection unit extinguishes the light at the predetermined wavelength and that extracts object detection regions that are regions with a luminance higher than a predetermined value, in which the orientation estimation unit can estimate the own orientation on the basis of the object detection regions.

The object detection region extraction unit can extract object detection regions in the difference image that are regions with a luminance higher than a predetermined value and with an area larger than a predetermined area.

The signal processing apparatus can further include a first feature point extraction unit that extracts first feature points that are centers of gravity of the regions extracted as the object detection regions, in which the orientation estimation unit can estimate the own orientation on the basis of information of the first feature points including the centers of gravity.

The signal processing apparatus can further include: an imaging unit that takes an image of a range where the light projection unit projects the light at the predetermined wavelength; a second feature point extraction unit that extracts second feature points including corners from the image taken by the imaging unit; an image usage orientation estimation unit that estimates an orientation on the basis of the second feature points including the corners; and an integration unit that integrates an estimation result of the own orientation obtained based on the image taken by the light-receiving unit and an image usage orientation estimation result that is the orientation estimated by the image usage orientation estimation unit.

The signal processing apparatus can further include: an acquisition unit that acquires GPS (Global Positioning System) data and IMU (Inertial Measurement Unit) data; and a GPS IMU usage orientation estimation unit that estimates an orientation on the basis of the GPS data and the IMU data acquired by the acquisition unit, in which the integration unit can integrate the estimation result of the own orientation based on the image taken by the light-receiving unit, the image usage orientation estimation result that is the orientation estimated by the image usage orientation estimation unit, and a GPS IMU usage orientation estimation result that is the orientation estimated by the GPS IMU usage orientation estimation unit.

The signal processing apparatus can further include a data acquisition situation detection unit that detects a data acquisition situation of the light-receiving unit, a data acquisition situation of the imaging unit, and a data acquisition situation of the GPS data and the IMU data, in which the integration unit can weight and integrate the estimation result of the own orientation, the image usage orientation estimation result, and the GPS IMU usage orientation estimation result on the basis of the data acquisition situation of the light-receiving unit, the data acquisition situation of the imaging unit, and the data acquisition situation of the GPS data and the IMU data.

The integration unit can use a Bayesian filter or an EKF (Extended Kalman Filter) to integrate the estimation result of the own orientation, the image usage orientation estimation result, and the GPS IMU usage orientation estimation result.

The orientation estimation unit can estimate the own orientation on the basis of SLAM (Simultaneous Localization And Mapping) using the information of the first feature points.

The object can include a reflector, a minor, a road sign, or a center line on a road.

The wavelength of the light projected by the light projection unit can be in a near-infrared band.

The light projection unit can project and extinguish light at a plurality of wavelengths at predetermined intervals.

An aspect of the present disclosure provides a signal processing method including: a light projection process of projecting light at a predetermined wavelength; a light-receiving process of taking an image of an object with a reflectance higher than a predetermined reflectance by receiving reflected light of the light projected in the light projection process and reflected by the object; and an orientation estimation process of estimating own orientation on the basis of the image taken in the light-receiving process.

An aspect of the present disclosure provides a program causing a computer to execute processes including: a light projection unit that projects light at a predetermined wavelength; a light-receiving unit that takes an image of an object with a reflectance higher than a predetermined reflectance by receiving reflected light of the light projected by the light projection unit and reflected by the object; and an orientation estimation unit that estimates own orientation on the basis of the image taken by the light-receiving unit.

An aspect of the preset disclosure provides a moving body including: a light projection unit that projects light at a predetermined wavelength; a light-receiving unit that takes an image of an object with a reflectance higher than a predetermined reflectance by receiving reflected light of the light projected by the light projection unit and reflected by the object; an orientation estimation unit that estimates own orientation on the basis of the image taken by the light-receiving unit; a situation analysis unit that analyzes a situation on the basis of the orientation estimated by the orientation estimation unit; a planning unit that generates an action plan on the basis of an analysis result of the situation analysis unit; and a motion control unit that controls a motion on the basis of the action plan.

In the aspects of the present disclosure, light is projected at a predetermined wavelength, an image of an object with a reflectance higher than a predetermined reflectance is taken by receiving reflected light of the projected light reflected by the object, and own orientation is estimated on the basis of the taken image.

Advantageous Effects of Invention

According to the aspects of the present disclosure, estimation accuracy of a self-position can be particularly improved.

