VR-based colliery fully mechanized mining equipment collision detection and early warning method
Technical Field
The invention relates to a remote control collision detection technology, in particular to a collision early warning detection method for three-machine equipment on a fully mechanized coal mining face.
Background
With the continuous development of coal mining technology, most coal mine enterprises in China have realized automatic and mechanized coal mining. However, in remote control operation of few people and unmanned working faces, the most common hidden dangers are mutual collision among fully mechanized mining devices and phenomena of frame squeezing, frame biting and frame falling of working face supports, so that how to efficiently and accurately detect the collision among the fully mechanized mining devices becomes a core problem of coal mine safety production. Mining conditions are typically monitored using sensors and visual measurements. However, due to fluctuation of external factors and limitation of the installation position of the sensor, the dynamic characteristic and the static characteristic of the sensor can be changed and unstable, so that the sensor cannot achieve the purpose of rapidness and accuracy in practical application of collision detection. With the rapid development of vision sensing technology and image processing technology, vision measurement has become one of the most popular non-contact measurement methods. Compared with other optical measurement methods, the visual measurement method does not need additional optical path auxiliary equipment, only needs the camera device, and can complete corresponding measurement through acquisition and analysis of images, but because underground roadway light is insufficient, and dust content is large, the problems of explosion and the like easily occur, and the information acquisition of the camera device is influenced, so the method is not suitable for complex coal mine environments.
Disclosure of Invention
The invention aims to provide a VR-based colliery fully-mechanized mining equipment collision detection and early warning method, which can quickly and accurately judge whether controlled objects intersect according to the motion tracks and the poses of all equipment in a scene, realize collision early warning detection among fully-mechanized mining face equipment, ensure the normal operation of fully-mechanized mining equipment in the mining process through artificial intervention and automatic obstacle avoidance of the equipment, and meet the requirements of high efficiency and real-time performance of a system.
The technical scheme of the invention is as follows: a colliery comprehensive mining equipment collision detection and early warning method based on VR is provided based on colliery comprehensive mining working face virtual simulation and remote control system, the system mainly comprises a virtual simulation and remote monitoring platform, a remote control platform, a data communication module and lower computer hardware, wherein the virtual simulation and remote monitoring platform is used for simulating the comprehensive mining working face environment and the motion state of three machines of equipment, the platform is constructed by modeling, rendering, assembling and other operations based on Unity3D development software, and is characterized in that the platform is constructed by transmitting rays through a collision detection module to collide with all equipment added with collision bodies in a virtual scene and returning collision information, the detected distance D between the equipment is compared with a distance threshold preset by the system by calculating the ray length between the rays and all the collision bodies as the distance D between the equipment is less than a certain threshold, the early warning detection module sends out an alarm to remind an operator to take corresponding measures, and the relative position between the devices is judged according to the prompt of the system, so that the aim of early warning detection is fulfilled;
setting two distance thresholds D according to working condition safety requirementsmax,DminThe distance D between the devices is divided into three regions: safe area, early warning area and dangerA danger area;
the ray lengths between the ray and all colliders were calculated as follows:
suppose the coordinates of the origin of a ray in space are A (x, y, z) and the coordinates of the center of the sphere of the spherical collision volume are O (x)0,y0,z0) And R represents the radius of the Sphere, the triggering area of the Ray-Sphere collision is as follows:
L=((x,y,z)|(x-x0)2+(y-y0)2+(z-z0)2≤R2the formula (1) is that a, B and c are respectively the length, width and height of a box collision body, any point B (x, y and z) in the space is taken as a ray origin, and the barycentric coordinate of the box body is O (x)0,y0,z0) Then the triggering area of the Ray-Box collision is:
if the coordinates of any point on the ray satisfy the constraint conditions L (x, y, z) in the formulas (1) and (2), the ray can be judged to intersect with the collision body, and the length of the ray is determined to be the distance D between the devices by calculating the distance from the starting point of the ray to the intersection point.
The collision detection module is used for emitting virtual rays between devices, and the emitted rays have two conditions: (1) transmitting a Ray along any vector direction at a certain Point, which can be realized by Physics. Raycast static function, (2) transmitting the Ray To a certain fixed Point on a screen, which can be realized by two API functions of Screen Point To Ray or Viewport Point To Ray; these virtual rays resemble an invisible reflected straight line and the device hitting the first collider stops firing and feeds back the detected collision information.
The specific detection process is as follows:
the first step is as follows: adding rigid bodies and collision bodies to all equipment models capable of colliding in a virtual scene, and setting an early warning distance threshold D between each group of rigid bodies easy to collide according to the working condition requirementmax,Dmin;
The second step is that: when the fully mechanized mining equipment starts to move, the collision is detectedThe measurement module emits virtual rays between devices, the operation interface displays collision information (collision object and collision distance D) between devices in a GUI window, and meanwhile, the system starts to judge D and Dmax,DminThe positional relationship between:
when D > DmanWhen the distance between the devices is in a safe area, the GUI window does not appear;
when D is presentmax>D>DminWhen the distance D between the devices enters an early warning area, the early warning detection module gives an alarm, the operation interface displays collision information between the devices through a GUI window, an operator is reminded that the devices are about to collide, and the motion state of each device needs to be adjusted through manual intervention, so that the devices are in reasonable positions;
when D is less than DminWhen the distance D between the devices enters a dangerous area, the early warning detection module gives an alarm, the operation interface displays the distance D between the devices through a GUI window, collision detection is needed at the moment, if collision occurs between the devices, the system adopts emergency braking, if collision does not occur, the virtual operation platform reads detection data of various sensors installed on the devices through the database at the moment, the motion poses of the three-computer devices are calculated, the motion states of the devices are adjusted according to the calculation results, the devices are located at reasonable positions, and automatic obstacle avoidance of the fully mechanized mining devices is achieved.
The invention has the beneficial effects that:
aiming at the problem that the collision between the devices cannot be accurately judged by the coal mine fully-mechanized working face virtual simulation and remote control system under the working condition, the collision detection and early warning monitoring of the three devices of the fully-mechanized working face are carried out in real time by transmitting virtual rays on a virtual interaction platform by utilizing the virtual ray detection technology and the sensor detection technology, so that the normal operation of the three devices is ensured. The method can also be popularized and applied to collision detection of other remote control systems.
Drawings
Fig. 1 is a flow chart of the collision warning detection operation of the present invention.
FIG. 2 is a diagram of a virtual simulation scenario of the present invention.
Fig. 3 is a collision detection schematic of the present invention.
Fig. 4 is a collision detection diagram of the present invention.
Fig. 5 is an early warning detection diagram of the present invention.
Detailed Description
As shown in fig. 1, the VR-based colliery fully mechanized mining equipment collision detection and early warning method is characterized in that: the system is provided based on the virtual simulation and remote control system of the coal mine fully mechanized coal mining face, and mainly comprises a virtual simulation and remote monitoring platform, a remote control platform, a data communication module and lower computer hardware. The virtual simulation platform is used for simulating the environment of the fully mechanized coal mining face and the motion state of the three-machine equipment, and the collision detection early warning function of the three-machine equipment is realized through a virtual ray detection technology on the platform.
In a virtual environment, rigid body components and collision components must be added to the target object to produce the collision effect. Rigid body components are added to the target object, so that physical interaction of the target object in a scene can be realized.
And secondly, adding a collision early warning detection module of three-machine equipment for the system, wherein the collision early warning detection module mainly comprises an early warning detection module and a collision detection module. After the system starts virtual ray detection, the collision detection module can detect the distance between each group of collision bodies, and when the distance between the devices is detected to be in an abnormal state, the early warning detection module is started to remind an operator to take corresponding collision avoidance measures.
The early warning detection is the key for guaranteeing the normal operation of the automatic coal mining process, and when the distance D between the devices is smaller than a certain threshold value, the early warning detection module can give an alarm to remind an operator to take corresponding measures. According to the working condition safety requirement, two distance threshold values D are setmax,DminThe distance D between the devices is divided into three regions: and the safety region, the early warning region and the dangerous region judge the relative position of the devices according to the system prompt, so that the early warning detection of the system is realized.
The collision detection module is realized by transmitting virtual rays between devices, and when the rays are transmitted, two conditions are usually adopted, (1) one Ray is transmitted at a certain Point along any vector direction and can be realized by a Physics. Raycast static function, and (2) the rays are transmitted To a certain fixed Point on a Screen and can be realized by two API functions, namely Screen Point To Ray or Viewport Point To Ray; these virtual rays resemble an invisible reflected straight line and the device hitting the first collider stops firing and feeds back the detected collision information. The implementation of the ray detection may be selected according to the actual requirements of the target object.
The method monitors the relative distance between the three devices in the working process, and the specific collision early warning detection process comprises the following steps:
the first step is as follows: adding rigid bodies and collision bodies to a model capable of colliding in virtual equipment and environment, and setting a distance threshold D between each group of rigid bodies easy to collide according to working condition requirementsmax,Dmin;
The second step is that: when the fully mechanized mining equipment starts to move, ray detection is started, the distance D between GUI window display equipment appears on an operation interface, and meanwhile, the system starts to judge D and Dmax,DminThe positional relationship between:
when D > DmaxWhen the distance D between the devices is in a safe area, a GUI window does not appear; when D is presentmax>D>DminWhen the distance D between the devices is in the early warning area, the early warning detection module can send out an alarm to prompt an operator to collide, and the motion state of each device needs to be adjusted through manual intervention, so that the devices are in reasonable positions;
when D is less than DminAnd if the collision does not occur, the pose of a collision object needs to be calculated, and the motion state of each device is adjusted according to the calculation result, so that the devices are in reasonable relative positions, and the automatic obstacle avoidance of the fully mechanized mining device is realized.
As shown in fig. 2, in a Unity3D virtual interaction platform, the building of a virtual scene of a fully mechanized mining face in a well and the modeling, rendering and assembling of a virtual three-machine device are completed. In a virtual environment, rigid body components and collision components are added to a target object, so that physical interaction of the object in a scene can be realized. A collision volume is a type of physical component that is added to the target device along with a rigid body to trigger a collision.
As shown in fig. 3, the system adopts a box-shaped collision body to ensure real-time performance and accuracy of collision detection between three machines of equipment, and is a virtual ray collision detection schematic diagram of three machines of equipment on a fully mechanized mining face, wherein a cube surrounding the equipment is a collision body added for different parts of the equipment, and a dotted line represents a virtual ray for detecting a distance between the equipment.
As shown in fig. 4, during the normal movement process of the coal mining machine and the hydraulic support, the virtual environment is detected by virtual rays in real time, and when the equipment is in a safe distance, the rays are dotted lines to show that the movement process is normal.
As shown in fig. 5, when the rocker arm rises to the initially determined early warning area, the roller and the mutual upper may collide, and the virtual ray immediately appears as a dotted line to prompt the operator to adopt corresponding manual control.
It should be emphasized that the embodiments described herein are illustrative rather than restrictive, and thus the present invention is not limited to the embodiments described in the detailed description, and that other embodiments may occur to those skilled in the art based on the teachings herein.