Disclosure of Invention
The invention provides an unmanned logistics trolley environment sensing method and system, and aims to solve the technical problems that an unmanned logistics trolley environment sensing technology in the prior art is poor in robustness, low in detection precision and the like.
In one aspect, the invention provides an environment sensing method for an unmanned logistics trolley, which comprises the following steps:
scanning surrounding environment information of the unmanned logistics trolley by at least two laser radars to generate an environment point cloud image, wherein the environment point cloud image comprises a plurality of point cloud data, and the ranging ranges of the at least two laser radars are different;
determining a target ground point cloud set and a target non-ground point cloud set in the plurality of point cloud data;
acquiring first local environment information of the unmanned logistics trolley through an ultrasonic radar, and fusing the first local environment information with the target non-ground point cloud set to generate a target point cloud image;
respectively acquiring at least two coordinate values of the same obstacle information in the target point cloud image according to the at least two laser radars;
and fusing the at least two coordinate values according to an optimal distributed estimation fusion algorithm to generate a fused coordinate value, and taking the fused coordinate value as the coordinate value of the obstacle information.
In a possible implementation manner of the present invention, the generating the point cloud image of the unmanned logistics trolley environment by at least two laser radars includes:
scanning surrounding environment information of the unmanned logistics trolley through a first laser radar to generate an initial point cloud image;
carrying out distortion correction on the initial point cloud image through a GPS/IMU (global positioning system/inertial measurement unit) to generate a corrected point cloud image;
and acquiring second local environment information of the unmanned logistics trolley through a second laser radar, and fusing the second local environment information and the correction point cloud image to generate the environment point cloud image.
In a possible implementation manner of the present invention, the distortion correction of the initial point cloud image by the GPS/IMU includes:
respectively acquiring first position and attitude information of a current frame and second position and attitude information of a previous frame adjacent to the current frame of the unmanned logistics trolley in a scanning period of the first laser radar through a GPS/IMU;
and carrying out distortion correction on the initial point cloud image through preset coordinate conversion, the first position and posture information and the second position and posture information.
In a possible implementation manner of the present invention, the first attitude information includes a first yaw angle, a first pitch angle, a first heading angle, and a displacement, and the second attitude information includes a second yaw angle, a second pitch angle, and a second heading angle; the distortion correction of the initial point cloud image through the preset coordinate conversion, the first position and posture information and the second position and posture information specifically comprises the following steps:
p’=Ripi+Ti
in the formula, p' is a coordinate value of each point cloud data in the initial point cloud image after distortion correction; r
iIs a total rotation matrix; p is a radical of
iThe coordinate values of each point cloud data in the initial point cloud image before distortion correction are obtained; t is
iIs a displacement matrix;
is an attitude matrix; c is the scanning period of the first laser radar; []
TIs a transposed matrix; t is t
iA time difference between a current frame and a previous frame adjacent to the current frame;
is a first yaw angle;
is a first pitch angle;
is a first course angle quantity; α is a second yaw angle; beta is a second pitch angle; gamma is a second course angle; x, y, z are the three coordinate components of the displacement.
In one possible implementation manner of the present invention, the determining a target ground point cloud set and a target non-ground point cloud set in the plurality of point cloud data includes:
determining an initial plane model;
determining a seed ground point cloud set and a seed non-ground point cloud set;
optimizing the initial plane model;
calculating an orthogonal projection distance between the point cloud data in the seed ground point cloud set and the optimized plane model, wherein if the orthogonal projection distance is smaller than a threshold distance, the point cloud data belongs to the seed ground point cloud set, and if the orthogonal projection distance is larger than or equal to the threshold distance, the point cloud data belongs to the seed non-ground point cloud set;
judging whether the optimization times of the initial plane model are smaller than threshold times, if so, optimizing the initial plane model again; if not, stopping optimizing the initial plane model; the seed ground point cloud set and the seed non-ground point cloud set are the target ground point cloud set and the target non-ground point cloud set respectively.
In one possible implementation manner of the present invention, the determining the seed ground point cloud set and the seed non-ground point cloud set includes:
sequencing the plurality of point cloud data according to a preset height sequence;
calculating an average height of the plurality of point cloud data;
traversing the plurality of point cloud data, and taking the point cloud data with the height smaller than the average height as an initial ground point set;
and calculating the orthogonal projection distance between the point cloud data in the initial ground point set and the initial plane model, wherein if the orthogonal projection distance is less than a threshold distance, the point cloud data belongs to the seed ground point cloud set, and if the orthogonal projection distance is greater than or equal to the threshold distance, the point cloud data belongs to the seed non-ground point cloud set.
In a possible implementation manner of the present invention, the first laser radar is a sixteen-line mechanical laser radar, and the second laser radar is a four-line solid state laser radar.
In a possible implementation manner of the present invention, the range of the sixteen-line mechanical laser radar is 20 m; the range of the four-line solid laser radar is 50 m.
On the other hand, the invention also provides an environment sensing system of the unmanned logistics trolley, which comprises the following components:
the system comprises a first perception module, a second perception module and a third perception module, wherein the first perception module is used for scanning surrounding environment information of the unmanned logistics trolley through at least two laser radars to generate an environment point cloud image, the environment point cloud image comprises a plurality of point cloud data, and the distance measurement ranges of the at least two laser radars are different;
a segmentation module for determining a target ground point cloud set and a target non-ground point cloud set in the plurality of point cloud data;
the second sensing module is used for obtaining first local environment information of the unmanned logistics trolley through an ultrasonic radar, and fusing the first local environment information with the target non-ground point cloud set to generate a target point cloud image;
the target detection module is used for respectively acquiring at least two coordinate values of the same obstacle information in the target point cloud image according to the at least two laser radars;
and the fusion module is used for fusing the at least two coordinate values according to an optimal distributed estimation fusion algorithm to generate a fusion coordinate value, and the fusion coordinate value is used as the coordinate value of the obstacle information.
The method comprises the steps of scanning surrounding environment information of the unmanned logistics trolley through at least two laser radars to generate an environment point cloud image, obtaining first local environment information of the unmanned logistics trolley through an ultrasonic radar after determining a target ground point cloud set and a target non-ground point cloud set in a plurality of point cloud data, and fusing the first local environment information and the target non-ground point cloud set to generate the target point cloud image. The target point cloud image is generated by at least two laser radars and the ultrasonic radar together, so that the robustness of environment perception of the unmanned logistics trolley can be improved, and the detection precision is improved.
Furthermore, the method and the device fuse at least two coordinate values according to a pre-optimal distributed estimation fusion algorithm to generate a fused coordinate value, and the fused coordinate value is used as the coordinate value of the obstacle information, so that the robustness and the accuracy of obstacle detection can be further improved.
Detailed Description
The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.
The invention provides an unmanned logistics trolley environment sensing method and system, which are respectively explained in detail below.
Fig. 1 is a schematic flow diagram of an embodiment of an environment sensing method for an unmanned logistics trolley according to an embodiment of the present invention, and as shown in fig. 1, the environment sensing method for an unmanned logistics trolley includes:
s101, scanning surrounding environment information of the unmanned logistics trolley through at least two laser radars to generate an environment point cloud image, wherein the environment point cloud image comprises a plurality of point cloud data, and the ranging ranges of the at least two laser radars are different;
s102, determining a target ground point cloud set and a target non-ground point cloud set in the plurality of point cloud data;
s103, obtaining first local environment information of the unmanned logistics trolley through an ultrasonic radar, and fusing the first local environment information and the target non-ground point cloud set to generate a target point cloud image;
s104, respectively acquiring at least two coordinate values of the same obstacle information in the target point cloud image according to at least two laser radars;
specifically, data correlation of at least two lidar is achieved by a Global Nearest Neighbor (GNN) algorithm.
And S105, fusing the at least two coordinate values according to an optimal distributed estimation fusion algorithm to generate a fused coordinate value, and taking the fused coordinate value as a coordinate value of the obstacle information.
The unmanned logistics trolley environment sensing method provided by the embodiment of the invention scans the surrounding environment information of the unmanned logistics trolley through at least two laser radars to generate an environment point cloud image, obtains the first local environment information of the unmanned logistics trolley through an ultrasonic radar after determining a target ground point cloud set and a target non-ground point cloud set in a plurality of point cloud data, and fuses the first local environment information and the target non-ground point cloud set to generate the target point cloud image. Namely: the target point cloud image is generated by at least two laser radars and the ultrasonic radar with different ranging ranges, so that the robustness of environment perception of the unmanned logistics trolley can be improved, and the detection precision is improved.
Furthermore, the method and the device fuse at least two coordinate values according to a pre-optimal distributed estimation fusion algorithm to generate a fused coordinate value, and the fused coordinate value is used as the coordinate value of the obstacle information, so that multi-target tracking can be realized, and the robustness and the accuracy of obstacle detection are further improved.
Further, in some embodiments of the present invention, the environmental information around the unmanned logistics trolley is scanned by a first laser radar and a second laser radar, and the first laser radar is a sixteen-line mechanical laser radar and the second laser radar is a four-line solid state laser radar.
Specifically, the range of the sixteen-line mechanical laser radar is 20m, the vertical detection angle is 30 °, and the horizontal detection angle is 360 °. The range of the four-line solid laser radar is 50m, the vertical detection angle is 3.2 degrees, and the horizontal detection angle is 110 degrees. The range of the ultrasonic radar is 5m, and the horizontal detection angle is 60 degrees.
The introduction of the ultrasonic radar can compensate the driving blind area of the sixteen-line laser radar; the four-wire solid laser radar solves the problems that sixteen-wire laser radar is low in vertical resolution, road edge information cannot be effectively extracted, and effective return rate of remote point clouds is low.
Specifically, at least two coordinate values are fused according to an optimal distributed estimation fusion algorithm, and the generated fusion coordinate value is as follows: and respectively calculating at least two weights which are in one-to-one correspondence with the at least two coordinate values, and fusing according to the weights and the corresponding coordinate values to generate fused coordinate values.
It should be understood that: when the distance between the obstacle information and the unmanned logistics trolley is smaller than 20m, the weight of the sixteen-line mechanical laser radar is larger than that of the four-line solid-state laser radar, and when the distance between the obstacle information and the unmanned logistics trolley is larger than 20m, the weight of the sixteen-line mechanical laser radar is smaller than that of the four-line solid-state laser radar.
Further, in some embodiments of the present invention, as shown in fig. 2, S101 includes:
s201, scanning surrounding environment information of the unmanned logistics trolley through a first laser radar to generate an initial point cloud image;
specifically, the first laser radar scans the surrounding environment information of the unmanned logistics trolley, and generates an initial point cloud image by adopting Euclidean clustering of different clustering radiuses and clustering point transportation according to the distance.
S202, distortion correction is carried out on the initial point cloud image through a GPS/IMU, and a corrected point cloud image is generated;
s203, collecting second local environment information of the unmanned logistics trolley through a second laser radar, and fusing the second local environment information and the correction point cloud image to generate an environment point cloud image.
Through the setting, the distortion of the initial point cloud image can be corrected, and the environment perception capability of the unmanned logistics trolley is further improved.
Further, as shown in fig. 3, S202 includes:
s301, respectively acquiring first position information of a current frame and second position information of a previous frame adjacent to the current frame of the unmanned logistics trolley in a scanning period of a first laser radar through a GPS/IMU;
s302, distortion correction is carried out on the initial point cloud image through preset coordinate conversion, the first position and posture information and the second position and posture information.
Specifically, the first attitude information includes a first yaw angle, a first pitch angle, a first course angle and displacement, and the second attitude information includes a second yaw angle, a second pitch angle and a second course angle; s302 specifically comprises the following steps:
p’=Ripi+Ti
in the formula, p' is a coordinate value of each point cloud data in the initial point cloud image after distortion correction; r
iIs a total rotation matrix; p is a radical of
iThe coordinate values of each point cloud data in the initial point cloud image before distortion correction are obtained; t is
iIs a displacement matrix;
is an attitude matrix; c is the scanning period of the first laser radar; []
TIs a transposed matrix; t is t
iA time difference between a current frame and a previous frame adjacent to the current frame;
is a first yaw angle;
is a first pitch angle;
is a first course angle quantity; α is a second yaw angle; beta is a second pitch angle; gamma is a second course angle; x, y, z are three coordinate components of the displacement; r
x,R
y,R
zThree coordinate components of displacement are respectively a rotation matrix around an X-axis, a Y-axis and a Z-axis.
Further, in some embodiments of the present invention, as shown in fig. 4, S102 includes:
s401, determining an initial plane model;
wherein, in some embodiments of the invention, the initial planar model is a linear model.
S402, determining a seed ground point cloud set and a seed non-ground point cloud set;
s403, optimizing the initial plane model;
s404, calculating an orthogonal projection distance between the point cloud data in the seed ground point cloud set and the optimized plane model, wherein if the orthogonal projection distance is smaller than a threshold distance, the point cloud data belongs to the seed ground point cloud set, and if the orthogonal projection distance is larger than or equal to the threshold distance, the point cloud data belongs to the seed non-ground point cloud set;
s405, judging whether the optimization times of the initial plane model are smaller than the threshold times, if so, repeating S403-S404; if not, stopping optimizing the initial plane model; the seed ground point cloud set and the seed non-ground point cloud set are respectively a target ground point cloud set and a non-ground point cloud set.
Further, as shown in fig. 5, S402 includes:
s501, sequencing the plurality of point cloud data according to a preset height sequence;
s502, calculating the average height of a plurality of point cloud data;
s503, traversing a plurality of point cloud data, and taking the point cloud data with the height smaller than the average height as an initial ground point set;
s504, calculating an orthogonal projection distance between the point cloud data in the initial ground point set and the initial plane model, wherein if the orthogonal projection distance is smaller than a threshold distance, the point cloud data belongs to a seed ground point cloud set, and if the orthogonal projection distance is larger than or equal to the threshold distance, the point cloud data belongs to a seed non-ground point cloud set.
Through the arrangement, the drivable area of the unmanned logistics trolley can be determined for subsequent path planning of the unmanned logistics trolley.
By identifying the outliers and deleting the outliers, the details of the environmental characteristics can be kept while the noise points of rain and snow are effectively removed, and the robustness and the accuracy of the environment perception of the unmanned logistics trolley are further improved.
Further, as shown in fig. 6, for the hardware platform of the unmanned logistics trolley environment sensing method provided by the embodiment of the invention, the hardware platform processes sensing data from sixteen-line mechanical lidar, four-line solid-state lidar and ultrasonic radar by using NVIDIA TX2 of a Robot Operating System (ROS), and one CAN channel of TX2 is connected with the ultrasonic radar and the GPS/IMU. The notification data of the sixteen-wire mechanical lidar, the four-wire solid-state lidar, is transmitted to TX2 through ethernet. Finally, the detected environment information is output to CompactRIO, which is a lower computer for path planning and motion control, through another CAN channel of TX 2.
On the other hand, in order to better implement the method for sensing the environment of the unmanned logistics trolley in the embodiment of the present invention, on the basis of the method for sensing the environment of the unmanned logistics trolley, as shown in fig. 7, correspondingly, the embodiment of the present invention further provides a system for sensing the environment of the unmanned logistics trolley, where the system 700 for sensing the environment of the unmanned logistics trolley includes:
the first perception module 701 is used for scanning surrounding environment information of the unmanned logistics trolley through at least two laser radars to generate an environment point cloud image, wherein the environment point cloud image comprises a plurality of point cloud data, and the distance measurement ranges of the at least two laser radars are different;
a segmentation module 702 configured to determine a target ground point cloud set and a target non-ground point cloud set in the plurality of point cloud data;
the second sensing module 703 is configured to obtain first local environment information of the unmanned logistics trolley through an ultrasonic radar, and fuse the first local environment information with a target non-ground point cloud set to generate a target point cloud image;
a target detection module 704, configured to collect at least two coordinate values of the same obstacle information in the target point cloud image according to at least two laser radars, respectively;
the fusion module 705 is configured to fuse the at least two coordinate values according to an optimal distributed estimation fusion algorithm to generate a fusion coordinate value, and use the fusion coordinate value as the coordinate value of the obstacle information.
On the other hand, an embodiment of the present invention further provides a computer device, which integrates any one of the unmanned logistics trolley environment sensing systems provided by the embodiment of the present invention, where the computer device includes:
one or more processors;
a memory; and
one or more application programs, wherein the one or more application programs are stored in the memory and configured to be executed by the processor to perform the steps of the unmanned logistics car environment awareness method in any of the above embodiments of the unmanned logistics car environment awareness method.
Specifically, in this embodiment, the computer device can thus implement various functions, as follows:
scanning surrounding environment information of the unmanned logistics trolley by at least two laser radars to generate an environment point cloud image, wherein the environment point cloud image comprises a plurality of point cloud data, and the ranging ranges of the at least two laser radars are different;
determining a target ground point cloud set and a target non-ground point cloud set in the plurality of point cloud data;
acquiring first local environment information of the unmanned logistics trolley through an ultrasonic radar, and fusing the first local environment information with the target non-ground point cloud set to generate a target point cloud image;
respectively acquiring at least two coordinate values of the same obstacle information in the target point cloud image according to the at least two laser radars;
and fusing the at least two coordinate values according to an optimal distributed estimation fusion algorithm to generate a fused coordinate value, and taking the fused coordinate value as the coordinate value of the obstacle information.
It will be understood by those skilled in the art that all or part of the steps of the methods of the above embodiments may be performed by instructions or by associated hardware controlled by the instructions, which may be stored in a computer readable storage medium and loaded and executed by a processor.
To this end, an embodiment of the present invention provides a computer-readable storage medium, which may include: read Only Memory (ROM), Random Access Memory (RAM), magnetic or optical disks, and the like. The system comprises a storage device, a processor and a computer program, wherein the storage device stores the computer program, and the computer program is loaded by the processor to execute the steps of any one of the unmanned logistics trolley environment perception methods provided by the embodiment of the invention. For example, the computer program may be loaded by a processor to perform the steps of:
scanning surrounding environment information of the unmanned logistics trolley by at least two laser radars to generate an environment point cloud image, wherein the environment point cloud image comprises a plurality of point cloud data, and the ranging ranges of the at least two laser radars are different;
determining a target ground point cloud set and a target non-ground point cloud set in the plurality of point cloud data;
acquiring first local environment information of the unmanned logistics trolley through an ultrasonic radar, and fusing the first local environment information with the target non-ground point cloud set to generate a target point cloud image;
respectively acquiring at least two coordinate values of the same obstacle information in the target point cloud image according to the at least two laser radars;
and fusing the at least two coordinate values according to an optimal distributed estimation fusion algorithm to generate a fused coordinate value, and taking the fused coordinate value as the coordinate value of the obstacle information.
In a specific implementation, each unit or structure may be implemented as an independent entity, or may be combined arbitrarily to be implemented as one or several entities, and the specific implementation of each unit or structure may refer to the foregoing method embodiment, which is not described herein again.
The method and the system for sensing the environment of the unmanned logistics trolley provided by the invention are described in detail, a specific example is applied in the method to explain the principle and the implementation mode of the invention, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for those skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.