Sensor calibration method and robot

Abstract

The application provides a sensor calibration method, a robot and a computer readable storage medium, wherein a sensor is installed on a robot in a preset pose, the sensor can acquire image information and / or point cloud data in a front area, the sensor calibration method comprises the following steps: controlling the sensor to scan a calibration plane and a calibration object with a preset shape, the calibration object is protrudingly arranged in the calibration plane; acquiring a relative position relationship between the calibration object and the robot; calculating an offset of the sensor according to a scanning result of the calibration plane and the calibration object and based on the relative position relationship between the calibration object and the robot, the offset comprises an angle deviation of the sensor relative to the preset pose; and correcting the sensor according to the offset of the sensor. In the embodiment of the application, the limitation of the calibration plane and the calibration object is much smaller than that of a standardized calibration space, the sensor calibration method can be applied in most common scenes, and the cost of robot sensor calibration is reduced.

Description

TECHNICAL FIELD

[0001] The present application generally relates to the field of robots and control technology thereof, and particularly relates to a sensor calibration method and a robot. BACKGROUND

[0002] A robot is a device controlled by an intelligent control system, which can be applied to scenarios such as precision machining, narrow environment, dangerous environment, etc., to replace part of manual operation. A sensor is an essential component of a robot, which is used to obtain information about the environment around the robot to guide the subsequent actions of the robot. The sensor is fixedly installed on the robot, and the relative position between the sensor and the robot is fixed. The image information and / or point cloud information obtained by the sensor can reflect the relative positional relationship between the surrounding environment and the robot. However, due to the limitation of machining precision, and the influence of factors such as collision and jolt of the robot during use, the sensor often deviates from the preset pose. If the preset coordinate conversion relationship is used for conversion, it will lead to deviation in the position information of the surrounding environment, and the robot may not be accurately positioned during operation, or even collide. Therefore, it is necessary to calibrate the sensor installed on the robot, and adjust the relative positional relationship between the sensor and the robot, or optimize the coordinate conversion relationship.

[0003] The existing robot sensor calibration process needs to use a specific calibration space, scan the calibration space by using the sensor, obtain the offset of the sensor, and correct it. This process is mainly applied to the factory inspection process of robots. However, there is a spatial distance between the application position of the robot and the production position of the robot. The deviation of the sensor that occurs during the application of the robot needs to be repaired by returning the robot to the factory, which requires a large amount of time and economic cost.

[0004] The contents of the background section merely represent the knowledge of the inventors, and do not necessarily represent the existing technology in the field. SUMMARY

[0005] In view of one or more defects in the prior art, the present application provides a sensor calibration method. The sensor is installed on a robot in a preset pose, and the sensor can obtain image information and / or point cloud data in a front area. The sensor calibration method comprises the following steps:

[0006] controlling the sensor to scan a calibration plane and a calibration object with a preset shape, the calibration object being protrudingly arranged in the calibration plane;

[0007] obtaining the relative positional relationship between the calibration object and the robot;

[0008] According to the scanning result of the calibration plane and the calibration object, and based on the relative position relationship between the calibration object and the robot, the offset of the sensor is calculated, the offset including an angle deviation of the sensor relative to a preset pose;

[0009] The sensor is corrected according to the offset of the sensor.

[0010] According to one aspect of the present application, wherein the calibration object has a front plane facing the sensor, the front plane having a preset included angle with the calibration plane;

[0011] The step of calculating the offset of the sensor includes:

[0012] A first normal vector is obtained, the first normal vector being a normal vector of the front plane of the calibration object;

[0013] According to the first normal vector, a yaw angle of the sensor relative to a preset pose is calculated.

[0014] According to one aspect of the present application, wherein the step of calculating the offset of the sensor further includes:

[0015] A second normal vector is obtained, the second normal vector being a normal vector of the calibration plane;

[0016] According to the second normal vector, a roll angle and a pitch angle of the sensor relative to a preset pose are calculated.

[0017] According to one aspect of the present application, wherein the offset of the sensor further includes a distance offset of the sensor relative to a preset pose;

[0018] The step of calculating the offset of the sensor further includes:

[0019] A first feature point of the calibration object is obtained, and a coordinate of the first feature point in a field of view of the sensor in a preset pose is calculated;

[0020] According to the coordinate of the first feature point in the field of view of the sensor in the preset pose and a coordinate of the first feature point in the field of view of the sensor in a current pose, an offset of the sensor relative to the preset pose in a normal direction of the calibration plane is calculated.

[0021] According to one aspect of the present application, wherein the step of calculating the offset of the sensor further includes:

[0022] A second feature point of the calibration object is obtained, and a coordinate of the second feature point in the field of view of the sensor in the preset pose is calculated; the second feature point is the same as or different from the first feature point;

[0023] According to the coordinates of the second feature point in the field of view of the sensor in the preset pose and the coordinates of the second feature point in the field of view of the sensor in the current pose, the offset of the sensor in the parallel plane of the calibration plane is calculated.

[0024] According to an aspect of the present application, wherein the step of calculating the offset of the sensor further comprises: calculating the distance offset of the sensor relative to the preset pose after the yaw angle, the roll angle and the pitch angle of the sensor are corrected according to the yaw angle, the roll angle and the pitch angle deviation of the sensor relative to the preset pose.

[0025] According to an aspect of the present application, wherein the step of obtaining the relative position relationship between the calibration object and the robot comprises: obtaining the relative position relationship between the calibration object and the robot by a measuring device, or manually inputting the relative position relationship between the calibration object and the robot; the relative position relationship between the calibration object and the robot includes the coordinates of the first feature point and the second feature point in the field of view of the sensor in the preset pose.

[0026] According to an aspect of the present application, wherein in the field of view of the sensor in the preset pose, the normal of the calibration plane is taken as the Z direction, the direction of the projection of the field of view of the sensor in the preset pose on the calibration plane is taken as the X direction, and the direction perpendicular to the Z direction and the X direction in space is taken as the Y direction.

[0027] The step of calculating the offset of the sensor comprises:

[0028] According to the angle between the first normal vector and the plane in which the X direction and the Z direction are located, the yaw angle of the sensor is calculated.

[0029] According to the angle between the second normal vector and the plane in which the X direction and the Z direction are located, and the angle between the Y direction and the plane in which the Z direction is located, the roll angle and the pitch angle of the sensor are calculated.

[0030] According to the deviation of the first feature point in the Z direction, the offset of the sensor in the Z direction is calculated.

[0031] According to the deviation of the second feature point in the X direction and the Y direction, the offset of the sensor in the X direction and the Y direction is calculated.

[0032] According to an aspect of the present application, wherein the process of correcting the sensor comprises:

[0033] According to the offset of the sensor, the installation position of the sensor on the robot is adjusted; or

[0034] According to the offset of the sensor, the scanning data obtained by the sensor is inversely compensated.

[0035] According to an aspect of the present application, the present application further comprises a robot, which comprises:

[0036] a body;

[0037] a sensor disposed on the body; and

[0038] a control system in communication with the sensor and configured to perform the sensor calibration method as previously described.

[0039] According to an aspect of the present application, the robot further comprises a distance sensor, the distance sensor is fixed in relative position with the preset pose of the sensor, the field of view of the distance sensor at least partially overlaps with the field of view of the sensor, and the relative position relationship between the calibration object and the robot is obtained through the distance sensor; the distance sensor is in communication with the control system.

[0040] According to an aspect of the present application, the present application further comprises a computer readable storage medium, the computer readable storage medium comprises computer executable commands stored thereon, the executable commands implement the sensor calibration method as previously described when executed by a processor.

[0041] Compared with the prior art, the embodiments of the present application provide a sensor calibration method, which can calibrate the sensor on the robot by using the calibration plane and the calibration object, obtain the offset of the sensor, and correct the sensor. The limitation of the calibration plane and the calibration object is much smaller than that of the standardized calibration space, the sensor calibration method can be applied in most common scenes, breaks through the limitation requirement of the scene in the sensor calibration process, can calibrate the sensor in the application scene of the robot, or reduces the cost of the robot sensor calibration by modifying the coordinate conversion parameters through networking. The present application further comprises a robot and a computer readable storage medium, which can implement the aforementioned sensor calibration method. BRIEF DESCRIPTION OF DRAWINGS

[0042] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate the embodiments of the present application, and are used to explain the present application, and do not constitute a limitation of the present application. In the drawings:

[0043] Figure 1 is a flowchart of the sensor calibration method in an embodiment of the present application;

[0044] Figure 2 is a flowchart of the sensor calibration method comprising the process of calculating the yaw angle in an embodiment of the present application;

[0045] Figure 3 is a flowchart of the sensor calibration method comprising the process of calculating the roll angle and the pitch angle in an embodiment of the present application;

[0046] Figure 4is a flowchart of a sensor calibration method comprising a process of calculating a normal offset of a calibration plane in an embodiment of the present application;

[0047] Figure 5 is a flowchart of a sensor calibration method comprising a process of calculating an in-plane offset of a calibration plane in an embodiment of the present application;

[0048] Figure 6 is a structural diagram of a robot in an embodiment of the present application;

[0049] Figure 7 is a structural block diagram of a robot in an embodiment of the present application. DETAILED DESCRIPTION

[0050] Hereinafter, only certain exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present application. Therefore, the drawings and the description are considered to be exemplary in nature rather than limiting.

[0051] In the description of the present application, it needs to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0052] In the description of the present application, it needs to be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected: it can be mechanical connection, or electrical connection or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0053] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature can include that the first and second features are in direct contact, or can include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature is "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the first feature is higher in horizontal height than the second feature. The first feature is "under", "below" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or only means that the first feature is lower in horizontal height than the second feature.

[0054] The following disclosure provides many different embodiments, or examples, for implementing different structures of the present application. For the purpose of simplifying the present application, the components and arrangements of the specific examples are described in the following. Of course, they are only examples and the purpose is not to limit the present application. In addition, the present application can repeatedly refer to numerals and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or arrangements discussed. In addition, the present application provides examples of various specific processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.

[0055] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, it should be understood that the preferred embodiments described herein are only for illustration and explanation of the present application, and are not intended to limit the present application.

[0056] Figure 1 The specific flow of the sensor calibration method 100 according to one embodiment of the present application is shown, and the detailed description is as follows. Figure 1 Detailed description.

[0057] The sensor is installed on the robot in a preset pose, and can obtain information in the area in front of the sensor, wherein the preset pose includes the position of the sensor installed on the robot and the angle of the sensor relative to the robot. For example, for common delivery robots, transfer robots and the like, the sensor is installed directly in front of the movement direction of the robot, and during the forward movement of the robot, image information and / or point cloud information in the range in front of the robot is obtained, and when an obstacle appears, the robot is controlled to stop moving or avoid according to the obtained information.

[0058] The sensor can be a color camera, a depth camera, an infrared camera, a structured light camera, a laser radar, etc., and the information obtained by different types of sensors can be different, such as image information and / or point cloud information. The sensor can also be multiple image or point cloud acquisition devices integrated together, and the specific determination is made according to the application scene and requirements of the robot.

[0059] In the process of robot transportation, debugging and long-time running, the sensor may deviate from its preset pose, i.e. the standard installation position, which may cause errors in the surrounding environment information obtained by the robot through the sensor, such as the inability to accurately determine the position and distance of the obstacle, the inability to accurately locate the target position, etc., affecting the safe operation of the robot, so it is necessary to recalibrate the sensor, adjust the installation pose of the sensor, or change the conversion parameters between the sensor coordinates and the robot coordinates to obtain accurate information of the surrounding environment relative to the robot. Considering the machining precision and stability of the sensor, preferably, the sensor is corrected only by adjusting the coordinate conversion parameters, without adjusting the physical installation position of the sensor.

[0060] In step S101, the sensor is controlled to scan a calibration plane and a calibration object with a preset shape, wherein the calibration object is initially arranged in the calibration plane. The calibration plane is a flat plane within the field of view of the sensor, and for a robot placed on the ground, the ground is preferably used as the calibration plane, which is easy to obtain and can calibrate the sensor in most working scenes of the robot. The calibration object is arranged in the calibration plane and protrudes from the calibration plane. The preset shape of the calibration object can be a standard shape, such as a cuboid or a prism with known size parameters, or other non-standard shapes, which are not limited in the embodiment. The sensor obtains image information and / or point cloud information of the calibration plane and the calibration object by scanning the calibration plane and the calibration object, which is used for subsequent step processing.

[0061] In step S102, the relative position relationship between the calibration object and the robot is obtained. This step and step S101 can be performed simultaneously or in any order, and are not limited to the order shown in Figure 1 The relative position relationship between the calibration object and the robot includes the distance and azimuth angle between the calibration object and the robot, i.e. the coordinate value of the calibration object in the robot coordinate system or the coordinate system when the sensor is in the preset pose is obtained in this step. In the embodiment, the calibration object is a solid entity with a certain volume, so the coordinate value of the calibration object in the robot coordinate system is a continuous range value in a set.

[0062] According to the preferred embodiment of the application, the relative position relationship between the calibration object and the robot can be obtained by other measuring devices, such as other sensors arranged on the robot in the standard installation position, or by using external measuring devices of the robot to obtain the relative position relationship between the calibration object and the robot, and the relative position relationship is input into the system executing the sensor calibration method 100 by manual input.

[0063] At step S103, the offset of the sensor is calculated according to the scanning results of the calibration plane and the calibration object and based on the relative position relationship between the calibration object and the robot, the offset including an angle deviation of the sensor relative to the preset pose, and further, the angle deviation of the sensor can be decomposed into angle deviations in three mutually perpendicular directions according to the three-dimensional direction of the sensor at the preset pose. In the specific embodiment of the application, the angle deviations in the three directions are calculated respectively or simultaneously. In actual application, the offset of the sensor relative to the preset pose can also include a distance deviation, which can also be decomposed into three mutually perpendicular directions according to the three-dimensional direction of the sensor at the preset pose.

[0064] At step S104, the sensor is corrected according to the offset of the sensor, and preferably, the sensor is corrected by adjusting the conversion relationship between the sensor coordinate system and the robot coordinate system, so that the information obtained by the sensor can reflect the environment around the robot as much as possible.

[0065] As described above, the angle deviation of the sensor relative to the preset pose can be decomposed into three components in the three-dimensional direction at the preset pose, and in the preferred embodiment of the application, the three components of the angle deviation are yaw angle, roll angle and pitch angle. The yaw angle represents the angle by which the front direction of the sensor deviates from the front direction of the sensor at the preset pose in a plane parallel to the calibration plane, for example, the yaw angle represents the angle by which the projection of the optical axis of the optical camera in the calibration plane deviates from the projection of the optical axis of the optical camera at the preset pose in the calibration plane. Figure 2 The process of the sensor calibration method 200 for calculating the yaw angle of the sensor according to the preferred embodiment of the application is shown, and the following will be described in detail with reference to Figure 2 The detailed description will be given.

[0066] In this embodiment, the calibration object has a front plane facing the sensor, and the front plane of the calibration object has a preset included angle with the calibration plane, that is, the included angle between the front plane and the calibration plane is known, which can be determined by setting a suitable shape of the calibration object, for example, a certain plane of the calibration object facing the sensor is set as the front plane, the calibration object is fixedly placed on the calibration plane, and then the included angle between the front plane and the calibration plane is equal to the included angle between the front plane and the support plane of the calibration object, and the included angle between the front plane and the support plane is known when the preset shape of the calibration object is known. Preferably, the front plane is perpendicular to the calibration plane to simplify the calculation process. The front plane facing the sensor means that the front plane is located within the field of view of the sensor.

[0067] The steps S201, S202 and S205 in the sensor calibration method 200 are substantially the same as the steps S101, S102 and S104 in the sensor calibration method 100, and will not be described herein again. In step S203, a first normal vector is obtained, wherein the first normal vector is a normal vector of a front plane of the calibration object, and the first normal vector can be obtained by scanning the front plane by the sensor, obtaining the distance and angle relationship between the front plane and the sensor, or obtaining the point cloud data of the front plane.

[0068] In step S204, the yaw angle of the sensor relative to the preset pose is calculated according to the first normal vector, and after the yaw angle is obtained, the yaw angle offset of the sensor is corrected in step S205.

[0069] Specifically, the normal of the calibration plane is taken as the Z direction, the direction of the projection of the middle line of the field of view of the sensor in the preset pose on the calibration plane is taken as the X direction, and the direction perpendicular to the Z direction and the X direction in the space is taken as the Y direction. In the preferred embodiment of the present application, the coordinate axes in the robot coordinate system are parallel to the XYZ directions.

[0070] The yaw angle of the sensor can be calculated by the angle between the first normal vector and the plane where the X direction and the Z direction are located. The projection of the first normal vector on the calibration plane can be obtained according to the preset angle between the front plane and the calibration plane, and when the front plane is perpendicular to the calibration plane, the direction of the projection of the first normal vector on the calibration plane is parallel to the X direction. The difference between the actual detection value and the ideal value calculated according to the relative position relationship between the calibration object and the robot is the yaw angle of the sensor.

[0071] In the preferred embodiment of the present application, the front plane is perpendicular to the calibration plane, and the front plane is perpendicular to the X direction, i.e., the front plane of the calibration object faces the middle line of the field of view of the sensor in the preset pose, so that the ideal value of the first normal vector is parallel to the X direction, and the first normal vector calculated according to the actual data obtained by the sensor scanning can deviate from the ideal value of the first normal vector, and the angle between the projection of the detection value of the first normal vector on the calibration plane and the X direction is the yaw angle deviation between the sensor and the preset pose. In other embodiments of the present application, the angle between the front plane and the calibration plane can be obtained according to the preset shape of the calibration object, and the angle between the front plane and the X direction can be calculated according to the relative position relationship (azimuth angle) between the calibration object and the robot, so that the yaw angle of the sensor relative to the preset pose can also be calculated when the front plane does not satisfy the conditions of being perpendicular to the calibration plane and / or being perpendicular to the X direction, and the above embodiment is only a preferred embodiment of the present application to simplify the calculation process.

[0072] Figure 3The specific flow of the sensor calibration method 300 according to the preferred embodiment of the present application is shown, which comprises the process of calculating the roll angle and the pitch angle of the sensor relative to the standard pose, wherein the step S301, the step S302 and the step S305 are basically the same as the step S101, the step S102 and the step S104 in the sensor calibration method 100.

[0073] In the step S303, a second normal vector is obtained, wherein the second normal vector is the normal vector of the calibration plane. Specifically, the sensor can scan the calibration plane, and the normal vector of the calibration plane can be obtained according to the scanning data. In the step S304, the roll angle and the pitch angle of the sensor relative to the preset pose are calculated according to the normal vector of the calibration plane. Taking the XYZ direction as an example, the yaw angle is the angle offset of the sensor relative to the preset pose rotating around the Z direction, the roll angle is the angle offset of the sensor relative to the preset pose rotating around the X direction, and the pitch angle is the angle offset of the sensor relative to the preset pose rotating around the Y direction.

[0074] The second normal vector also has an ideal value (parallel to the Z direction), and the deviation between the obtained second normal vector and the ideal value of the second normal vector can be used to calculate the roll angle and the pitch angle of the sensor relative to the preset pose.

[0075] The angle between the second normal vector and the plane where the X direction and the Z direction are located, or the angle between the projection in the plane where the Y direction and the Z direction are located and the Z direction, is the roll angle of the sensor relative to the preset pose. The angle between the second normal vector and the plane where the Y direction and the Z direction are located, or the angle between the projection in the plane where the X direction and the Z direction are located and the Z direction, is the pitch angle of the sensor relative to the preset pose. After the corresponding angle values are calculated, the roll angle and the pitch angle of the sensor can be corrected by reverse compensation.

[0076] Further, according to the preferred embodiment of the present application, the offset of the sensor also includes the distance offset of the sensor relative to the preset pose. The distance offset of the sensor relative to the preset pose can be decomposed into three perpendicular directions according to the XYZ direction, and the components in the three directions are calculated respectively, and then the sensor is corrected according to the calculation results.

[0077] Figure 4 The specific flow of the sensor calibration method 400 according to the preferred embodiment of the present application is shown, which comprises the process of calculating the distance offset of the sensor relative to the preset pose in the normal direction of the calibration plane. Specifically, the step S401, the step S402 and the step S405 in the sensor calibration method 400 are basically the same as the step S101, the step S102 and the step S104 in the sensor calibration method 100, and will not be described in detail.

[0078] In step S403, a first feature point is acquired, and the coordinates of the first feature point within the field of view of the sensor in a preset pose are calculated. The first feature point is located on a calibration object. Preferably, a position with a shape feature can be preset on the calibration object to facilitate sensor identification or calculation of the coordinates of the first feature point. For example, this could be a vertex of the calibration object or the center point of a plane. The center point can be obtained by controlling the sensor to scan the plane and calculating based on the scan data. The coordinates of the first feature point within the field of view of the sensor in the preset pose can be understood as the coordinates of the first feature point within the sensor's own coordinate system or the robot's own coordinate system when the sensor is in the preset pose. Specifically, this can be calculated based on the relative positional relationship between the calibration object and the robot, as well as the preset shape of the calibration object.

[0079] In step S404, based on the coordinates of the first feature point within the field of view of the sensor in its preset pose and the coordinates of the first feature point within the field of view of the sensor in its current pose, the offset of the sensor relative to the preset pose in the normal direction of the calibration plane is calculated. The coordinates of the first feature point within the field of view of the sensor in its preset pose are the ideal value of the first feature point, and the coordinates of the first feature point within the field of view of the sensor in its current pose are the detected value of the first feature point. The deviation between these two values ​​in the normal direction of the calibration plane is the deviation of the sensor relative to the preset pose in the normal direction of the calibration plane.

[0080] In a preferred embodiment of the present invention, the normal direction of the calibration plane is the Z direction, and the deviation between the ideal value and the detected value of the first feature point in the Z direction is the offset of the sensor relative to the preset pose in the Z direction. Furthermore, the deviations between the ideal value and the detected value of the first feature point in the X and Y directions can also be used to calculate the deviation values ​​of the sensor relative to the preset pose in the X and Y directions.

[0081] In a preferred embodiment of the present invention, such as Figure 5 As shown, the sensor calibration method 500 specifically includes calculating the distance deviation of the sensor relative to the preset pose in the plane parallel to the calibration plane based on the second feature point. Steps S501, S502, and S505 in the sensor calibration method 500 are basically the same as steps S101, S102, and S104 in the sensor calibration method 100, and will not be described again.

[0082] In step S503, a second feature point is acquired, and its coordinates within the sensor's preset pose field of view are calculated. The second feature point is used to calculate the distance deviation of the sensor relative to the preset pose in a plane parallel to the calibration plane. According to the aforementioned embodiment, the first feature point in the sensor calibration method 400 can also be used to calculate the deviation value of the sensor relative to the preset pose in a plane parallel to the calibration plane; therefore, the second feature point can be the same as the first feature point. Preferably, the second feature point is different from the first feature point to improve the accuracy of the offset calculation. The second feature point can be a vertex of the calibration object or the face center of a plane. The coordinates of the second feature point within the sensor's preset pose field of view are calculated based on the relative positional relationship between the calibration object and the robot, and the preset structure of the calibration object. The specific calculation method is the same as the method for calculating the coordinates of the first feature point within the sensor's preset pose field of view in the aforementioned embodiment.

[0083] In step S504, the offset of the sensor in the plane parallel to the calibration plane is calculated based on the coordinates (ideal value) of the second feature point in the field of view under the sensor's preset pose and the coordinates (detected value) of the second feature point in the field of view under the sensor's current pose. Further, in the aforementioned XYZ directions, the offset of the sensor relative to the preset pose in the X and Y directions can be calculated using the deviations of the second feature point in the X and Y directions, respectively. According to a preferred embodiment of the present invention, the offset of the sensor relative to the preset pose in the three directions can be calculated using the first and second feature points located at different positions on the calibration object, and the errors can be compared or averaged to improve the accuracy of the offset calculation.

[0084] According to different embodiments of the present invention, the yaw angle, roll angle, and pitch angle deviations of the sensor relative to the preset pose, as well as the distance deviations of the sensor relative to the preset pose in three mutually perpendicular directions, can be calculated simultaneously or separately in different orders. Preferably, after calculating the yaw angle, roll angle, and pitch angle deviations of the sensor relative to the preset pose and correcting the Euler angles of the sensor relative to the preset pose, the distance offset of the sensor relative to the preset pose is calculated to avoid the sensor generating new Euler angle deviations when adjusting and correcting the distance offset of the sensor.

[0085] like Figure 6 and Figure 7 As shown, the present invention also includes an embodiment of a robot 1, wherein the robot 1 includes a main body 10, sensors 20, and a control system 30. The main body 10 is the main structural frame of the robot 1, and all components of the robot 1 are fixed to the main body, for example... Figure 6The main body 10 can be made of an alloy material or an organic material with fixed properties, and various components in the robot 1 are installed at corresponding positions in the main body 10 to achieve specific functions.

[0086] The sensor 20 is arranged on the main body 10, and the sensor 20 can be used to acquire image signals and / or point cloud signals of the front area. Specifically, according to the preferred embodiment of the present application, the sensor 20 can be a camera or a laser radar device suitable for the application of the robot 1, and the sensor 20 is in signal connection with the control system 30. As shown in Figure 6 According to the specific design of the robot 1, the sensor 20 can be arranged at the front of the main body 10, so that when the robot 1 moves forward, the sensor 20 can acquire the surrounding environment information in the front range of the robot 1, determine the position of the robot, and perform obstacle avoidance and other operations.

[0087] In actual use, the sensor 20 can deviate from its preset pose on the robot, and the sensor offset can be corrected by performing the sensor calibration method in the foregoing embodiments through the control system 30.

[0088] In the preferred embodiment of the present application, as shown in Figure 6 and Figure 7 The robot 1 further comprises a distance sensor 40, wherein the relative position of the distance sensor 40 to the preset pose of the sensor 20 is fixed, that is, the sensor 20 and the distance sensor 40 are arranged at fixed positions on the main body 10 of the robot 1, and the angles are fixed. The field of view range of the distance sensor 40 at least partially overlaps with the field of view range of the sensor 20, and the relative position relationship between the calibration object and the robot 1 is acquired through the distance sensor 40. Preferably, the distance sensor is a laser radar, which is arranged on the main body 10. The laser radar can rotate along a set plane, so that the photoelectric receiving array of the laser radar forms a scanning column surface, and the distance and azimuth angle of the calibration object relative to the robot can be obtained by scanning the calibration object. At the same time, the distance sensor 40 also communicates with the control system 30.

[0089] Specifically, the laser radar can be arranged at the opening of the main body 10 of the robot 1, and emit laser signals to detect the surrounding objects. The above-mentioned laser radar comprises a photoelectric receiving array and a laser emitting unit array, so that when the laser radar rotates along a set plane, the photoelectric receiving array can form a scanning column surface to obtain a larger scanning range, which is convenient for obtaining the details of the object shape and avoiding the situation that the robot 1 device bumps into obstacles. Optionally, the above-mentioned set plane can be a horizontal plane, so as to facilitate the object detection of the robot 1 device during the movement. In addition, other set planes can also be selected according to specific user needs, such as a vertical plane, and the present embodiment does not limit this.

[0090] In the preferred method embodiment of the present application, the robot 1 further comprises a movement device arranged on the main body 10 of the robot 1 and capable of driving the main body 10 of the robot 1 to move upon receiving driving and control. Specifically, the movement device is provided with at least two groups of driving wheels, each group of driving wheels is located at one side of the moving chassis of the robot 1, and the driving wheels are used to drive the robot 1 to move. The speed of the driving wheels is controlled by the control system 30, thereby driving the robot 1 to move. Preferably, the driving wheels on different sides of the moving chassis are controlled respectively, and the robot 1 is turned by controlling the driving wheels to rotate at different speeds.

[0091] Further, the moving unit is provided with two groups of driving wheels, one group of driving wheels is used as a left driving wheel, and the other group of driving wheels is used as a right driving wheel. The left driving wheel and the right driving wheel are located on opposite sides of the moving chassis. When the robot 1 needs to turn, the left driving wheel and the right driving wheel are controlled to rotate at different speeds to realize the turning of the robot 1. Optionally, the movement device can further comprise at least two groups of driven wheels, one group of driving wheels corresponds to one group of driven wheels, at least one group of driven wheels is used as a left driven wheel, and at least one group of driven wheels is used as a right driven wheel. The left driven wheel and the right driven wheel are used to assist the left driving wheel and the right driving wheel to drive the shell and the moving chassis of the robot 1 to move, thereby reducing the load pressure of the driving wheels and improving the stability of the robot 1. The driven wheels can also be arranged on the center line of the left driving wheel and the right driving wheel to evenly distribute the weight of the robot 1 as much as possible.

[0092] Optionally, the bottom of the moving chassis is provided with at least one turn signal unit, and each turn signal unit comprises at least one turn signal. The control system 30 can also control the turn signals in the turn signal unit to light up in a preset manner when the robot 1 turns. The robot 1 provided by the embodiment of the present application can remind pedestrians to pay attention and improve the motion safety of the robot 1 by controlling the turn signals to light up through the element controller when the robot 1 turns.

[0093] According to other embodiments of the present application, the robot 1 further comprises a function controller for user operation, a bottom controller for map generation and path planning, and an element controller for controlling the moving unit and the environment detection unit.

[0094] Preferably, the element controller controls the turn signals in the turn signal unit to light up in a preset manner when the speed difference between the driving wheels on both sides of the moving chassis is greater than a preset value. Further, the robot 1 further comprises a voice module electrically connected with the element controller, and the voice module is controlled to issue voice prompt information when the robot 1 turns.

[0095] According to an embodiment of the present application, a path planning method of a robot is also provided, which can be applied to any robot, and it should be noted that each step can be performed in sequence or simultaneously according to actual conditions, and the present application does not limit the sequence.

[0096] The robot path planning method provided by the present application comprises the following steps:

[0097] Firstly, a map of a working area of the robot is constructed, and a positioning map of a current working area is determined, wherein the positioning map is a map formed by mapping of an environment in which the robot is located. Specifically, the robot is configured with a collection sensor and a modeling processor, and the modeling processor models and constructs an environment map based on environment data collected by the collection sensor. In the present embodiment, the collection sensor comprises a laser radar, an ultrasonic sensor and an infrared sensor, and the working area data in which the robot is located is collected by the laser radar, the ultrasonic sensor and the infrared sensor, and the modeling processor creates a map based on the data collected by the sensors. In the process of creating the map, different map layers are generated by different sensors, such as a static layer, a dynamic obstacle layer, an ultrasonic layer, a visual layer, etc., and the positioning map for positioning and navigation of the robot is obtained by fusing the map layers.

[0098] Secondly, a path is planned according to the positioning map.

[0099] Further, the current position and the target position of the robot are determined according to the positioning map, the position of an obstacle is determined according to the positioning map, or a path is planned according to the current position, the target position and the position of the obstacle.

[0100] Specifically, the target position is a position set by a user or a position determined by a processing system of the robot to be moved to, wherein the target position can be a position to be moved to next in the moving process or a final position to be reached by the robot. The current position is real-time position information of the robot determined by a position sensor.

[0101] The position of an obstacle on the positioning map is determined by the positioning map. Through this embodiment, the robot can determine the position of the obstacle and plan a route without changing the navigation accuracy.

[0102] Finally, the robot is controlled to move according to the planned path.

[0103] According to a preferred embodiment of the present application, a computer readable storage medium is also provided, which comprises computer executable commands stored thereon, and the executable commands implement the sensor calibration method as described in the foregoing embodiments when executed by a processor.

[0104] Finally, it should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art will appreciate that modifications can be made to the technical solutions described in the foregoing embodiments, or some of the technical features thereof can be replaced by equivalent features. Any modifications, equivalent replacements, improvements, and the like made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A sensor calibration method, wherein a sensor is installed on a robot in a preset pose, the sensor is capable of acquiring image information and / or point cloud data in a front region, the sensor calibration method comprising: controlling the sensor to scan a calibration plane and a calibration object having a preset shape, the calibration object is protrudingly arranged in the calibration plane; acquiring a relative position relationship between the calibration object and the robot; calculating an offset of the sensor according to a scanning result of the calibration plane and the calibration object and based on the relative position relationship between the calibration object and the robot, the offset comprising an angle deviation of the sensor relative to the preset pose; correcting the sensor according to the offset of the sensor; wherein the calibration object has a front plane facing the sensor, the front plane and the calibration plane have a preset included angle; the step of calculating the offset of the sensor comprises: acquiring a first normal vector, the first normal vector being a normal vector of the front plane of the calibration object; calculating a yaw angle of the sensor relative to the preset pose according to the first normal vector; wherein the yaw angle represents an angle by which a front direction of the sensor deviates from a front direction of the sensor in the preset pose in a plane parallel to the calibration plane. 2.The sensor calibration method according to claim 1, wherein the step of calculating the offset of the sensor further comprises: acquiring a second normal vector, the second normal vector being a normal vector of the calibration plane; calculating a roll angle and a pitch angle of the sensor relative to the preset pose according to the second normal vector. 3.The sensor calibration method according to claim 2, wherein the offset of the sensor further comprises a distance offset of the sensor relative to the preset pose; the step of calculating the offset of the sensor further comprises: acquiring a first feature point of the calibration object and calculating a coordinate of the first feature point in a field of view of the sensor in the preset pose; calculating the offset of the sensor relative to the preset pose in a normal direction of the calibration plane according to the coordinate of the first feature point in the field of view of the sensor in the preset pose and a coordinate of the first feature point in the field of view of the sensor in a current pose of the sensor. 4.The sensor calibration method according to claim 3, wherein the step of calculating the offset of the sensor further comprises: acquiring a second feature point of the calibration object and calculating a coordinate of the second feature point in the field of view of the sensor in the preset pose; the second feature point is the same as or different from the first feature point; calculating the offset of the sensor in a parallel plane of the calibration plane according to the coordinate of the second feature point in the field of view of the sensor in the preset pose and a coordinate of the second feature point in the field of view of the sensor in the current pose of the sensor. calculating the distance offset of the sensor relative to the preset pose after correcting Euler angles of the sensor relative to the preset pose according to the yaw angle, the roll angle and the pitch angle of the sensor. acquiring the relative position relationship between the calibration object and the robot by a measuring device or manually inputting the relative position relationship between the calibration object and the robot; the relative position relationship between the calibration object and the robot comprises the coordinates of the first feature point and the second feature point in the field of view of the sensor in the preset pose. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5. The sensor calibration method of claim 4, wherein the step of calculating an offset for the sensor further comprises: ​ 6. The sensor calibration method according to claim 4, wherein the step of acquiring the relative positional relationship of the calibration object and the robot comprises: ​ ​ 7. The sensor calibration method of claim 5, wherein in the field of view of the sensor in the preset pose, the normal of the calibration plane is the Z direction, the direction of the projection of the field of view of the sensor in the preset pose on the calibration plane is the X direction, and the direction perpendicular to the Z direction and the X direction in the space is the Y direction. the yaw angle of the sensor is calculated according to the angle between the first normal vector and the plane in which the X direction and the Z direction lie; the roll angle and the pitch angle of the sensor are calculated according to the angle between the second normal vector and the plane in which the X direction and the Z direction lie, and the angle between the Y direction and the plane in which the Z direction lies; the offset of the sensor in the Z direction is calculated according to the deviation of the first feature point in the Z direction; the offsets of the sensor in the X direction and the Y direction are calculated according to the deviations of the second feature point in the X direction and the Y direction.

8. The sensor calibration method of any one of claims 1-7, wherein the process of correcting the sensor comprises: adjusting the installation position of the sensor on the robot according to the offsets of the sensor; or performing reverse compensation on the scan data obtained by the sensor according to the offsets of the sensor.

9. A robot comprising: a main body; a sensor disposed on the main body; and a control system in communication with the sensor and configured to perform the sensor calibration method of any one of claims 1-8.

10. The robot of claim 9, further comprising a distance sensor, the relative position of the distance sensor to the preset pose of the sensor is fixed, the field of view of the distance sensor at least partially overlaps with the field of view of the sensor, and the relative positional relationship between the calibration object and the robot is obtained by the distance sensor; the distance sensor is in communication with the control system.

11. A computer-readable storage medium comprising computer-executable commands stored thereon, the executable commands, when executed by a processor, implement the sensor calibration method of any one of claims 1-8. ​ ​

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