CN-121988007-A - Tennis receiving and dispatching intelligent vehicle based on machine vision and working method thereof

CN121988007ACN 121988007 ACN121988007 ACN 121988007ACN-121988007-A

Abstract

The invention provides a tennis ball receiving and dispatching intelligent vehicle based on machine vision and a working method thereof. The visual recognition part adopts a double-strategy fusion scheme, the precise three-dimensional pose of the tennis ball is obtained through matching of the contour and the height characteristics, and the automatic pickup module adopts a belt transmission integrated structure to realize continuous rolling, separation and warehousing of the tennis ball. The motion control module realizes accurate control on the path and the gesture based on the crawler-type differential chassis and a PID algorithm. The intelligent ball-serving module adopts a double-friction-wheel differential ball-serving structure, combines a pitch angle and horizontal angle adjusting mechanism, realizes multi-type ball serving such as upward rotation, downward rotation, flat striking and the like, and can dynamically adjust the ball-serving mode according to action characteristics of a trainer. The system can automatically complete the full processes of tennis ball identification, picking up, storing, moving and serving, improves training efficiency and automation level, reduces labor burden, and is suitable for tennis ball training with multiple scenes and multiple intensities.

Inventors

CHEN GANG
ZHAO SHUJIE
ZHAO BOSHENG
Zang Xiuyi
WU HAO
JIANG QILIANG
ZHOU BAOJU
SHEN JIALIN

Assignees

三明学院

Dates

Publication Date: 20260508
Application Date: 20251225

Claims (9)

1. The tennis receiving and dispatching intelligent vehicle based on machine vision is characterized by comprising a machine body frame, a vision identification module, an automatic pickup module, a motion control module, an intelligent service module, an upper computer and a lower computer, wherein the modules are integrated on the machine body frame, the upper computer is connected with the lower computer through serial communication, the upper computer realizes image processing and motion planning, and the lower computer realizes motion control, wherein: the visual recognition module comprises image acquisition equipment, a monocular visual recognition unit and a binocular visual recognition unit, wherein the monocular visual recognition unit comprises a CMOS camera corresponding to the CMOS camera; the binocular vision recognition unit comprises two CMOS cameras which are symmetrically distributed and construct a stereoscopic shooting structure, wherein the monocular vision recognition unit comprises a recognition algorithm based on HSV color characteristics, and the binocular vision recognition unit comprises a stereoscopic vision algorithm based on contour and height information; the automatic pickup module comprises a driving roller, a conveyor belt, a flexible baffle, a lifting plate, a ball storage basket, a ball guide plate, a tensioning device and a profile frame, wherein the surface of the conveyor belt is provided with a roller O-shaped groove and a guide bar, the driving roller is in transmission connection with the conveyor belt, the flexible baffle is fixed on one side of the input end of the conveyor belt, the lifting plate is obliquely arranged, the lower end of the lifting plate is connected with the conveyor belt, the upper end of the lifting plate extends to the inlet of the ball storage basket, the ball guide plate is arranged on the top of the conveyor belt and bends towards one side of the ball storage basket, the tensioning device is matched with the conveyor belt, and the profile frame is fixedly connected with the frame of the machine body; The motion control module comprises a crawler-type differential chassis, a microcontroller, a positioning system, a motor and a driver, wherein the crawler-type differential chassis comprises a left crawler belt, a right crawler belt and corresponding driving wheels, the motor is electrically connected with the driver and is in transmission fit with the driving wheels, and the microcontroller is respectively electrically connected with the positioning system and the driver; the intelligent pitching module comprises double friction wheels, a pitch angle adjusting mechanism, a horizontal angle adjusting mechanism and a stepping motor, wherein the double friction wheels are arranged at intervals in parallel, the stepping motor is respectively connected with the pitch angle adjusting mechanism and the horizontal angle adjusting mechanism in a transmission manner, the pitch angle adjusting mechanism is hinged with a mounting frame of the double friction wheels, and the horizontal angle adjusting mechanism is connected with a fixing seat of the pitch angle adjusting mechanism.
2. The tennis receiving and transmitting intelligent vehicle based on machine vision according to claim 1 is characterized in that the process of an identification algorithm based on HSV color characteristics comprises the steps of converting an image from RGB to HSV color space, carrying out image segmentation based on a preset tennis HSV color threshold value, extracting the outline of the image after denoising through median filtering, acquiring the circle center and the radius by adopting a minimum bounding circle, and screening out false detection by combining a set radius range, wherein the preset tennis HSV range is H channel 30-45 degrees, S channel 0-135 degrees, V channel 200-255 degrees, the median filtering side length is 5 pixels, and the screened radius range is 20-50 pixels; The conversion from RGB color space to HSV color space follows the following conversion: if H is less than 0, h=h+360.
3. The machine vision-based tennis ball receiving and dispatching intelligent vehicle is characterized in that in a stereoscopic vision algorithm based on contour and height information, a nonlinear camera model is used, monocular calibration is completed through a Zhang Zhengyou calibration method, then stereoscopic calibration is carried out to obtain the relative pose of a double camera, three-dimensional reconstruction accuracy is guaranteed, a round contour detection is carried out on a binocular image through a Hough gradient method, potential tennis ball targets are screened, a parallax map is generated through a BM block matching algorithm after stereoscopic correction, three-dimensional reconstruction is achieved through triangulation, a stereoscopic coordinate system is then converted into a vehicle body coordinate system, targets with Z coordinates of 20-80mm are screened according to standard tennis ball sizes, and interference is eliminated.
4. The intelligent car for receiving and transmitting tennis balls based on machine vision according to claim 1, wherein the driving roller of the automatic pick-up module drives the conveyor belt to operate, the flexible baffle pushes the tennis balls into the lifting plate and enters the ball storage basket along with the conveyor belt, the ball guide plate is used for reducing secondary collision of the balls, the roller O-shaped groove of the conveyor belt and the guide bar are used for avoiding offset, and the inclination angle of the lifting plate is adapted to the rolling speed and friction resistance of the tennis balls.
5. The tennis receiving and dispatching intelligent vehicle based on machine vision according to claim 1 is characterized in that the intelligent service module further comprises a player state identification unit and a service parameter optimization unit, wherein the player state identification unit identifies player states through an image sequence topology and detection algorithm, the service parameter optimization unit calculates service parameters through feature matching and a PID algorithm, the double friction wheels realize different rotation types of service such as upward rotation, downward rotation and horizontal stroke through rotation speed difference, and the pitch angle adjustment mechanism and the horizontal angle adjustment mechanism adopt a stepping motor position matching control algorithm to realize multi-angle adjustment.
6. The intelligent tennis receiving and transmitting vehicle based on machine vision according to claim 1 is characterized in that the motion control module controls the rotating speed of a motor by adopting PID, configures a linear walking algorithm and a point-to-point walking algorithm, monitors the course angle once every 50ms by recording an initial course angle and setting a course angle range, adjusts the speed of a driving wheel to correct the posture if the initial course angle exceeds the range, and the point-to-point walking algorithm adjusts the posture of a vehicle body by rotating to enable the advancing direction to point to the tennis ball, then starts the linear motion and corrects the course in real time.
7. The intelligent car for receiving and transmitting tennis balls based on machine vision according to claim 6, wherein in the PID control, e (t) is a deviation, which is a difference between a set value r (t) and an actual value y (t), the PID control is expressed as Wherein K p is a proportional coefficient, T 1 is an integral coefficient, and T d is a differential coefficient.
8. The intelligent tennis receiving and transmitting vehicle based on machine vision according to claim 6, wherein the kinematic model of the crawler chassis is based on the differential motion principle of two crawler belts, and the kinematic equation is as follows: note that, where v is the vehicle linear velocity, w is the angular velocity, The driving speeds of the left and right caterpillar tracks are respectively, Is the centroid coordinates, θ is the direction angle.
9. A working method of a tennis receiving and dispatching intelligent vehicle based on machine vision, the tennis receiving and transmitting intelligent vehicle based on machine vision according to any one of the claims 1-8, comprising the following steps: Step 1, starting and initializing, namely performing communication handshake between an upper computer and a lower computer, initializing a positioning system, establishing a coordinate system, and starting image acquisition by image acquisition equipment; step 2, tennis ball identification and positioning, namely selecting a corresponding identification algorithm according to illumination intensity and outputting tennis ball coordinates; step 3, motion planning and execution, namely calling a corresponding walking algorithm according to the tennis position, and driving the vehicle body to accurately drive to the tennis; Step 4, picking up tennis balls, namely continuously picking up tennis balls through a belt transmission structure and sending the tennis balls into a ball storage basket; and 5, launching tennis balls, namely dynamically adjusting the service parameters according to the states of players, and completing service through the double friction wheels and the gesture adjusting mechanism to form a closed loop for picking up, transporting and launching the tennis balls.

Description

Tennis receiving and dispatching intelligent vehicle based on machine vision and working method thereof Technical Field The invention relates to the technical field of intelligent tennis ball picking vehicles, in particular to a tennis ball receiving and dispatching intelligent vehicle based on machine vision and a working method thereof. Background With the popularization of tennis, the number of tennis fans is continuously increased, and the number of tennis courts is continuously increased. In tennis training, beginners need to perform a large number of service exercises, and picking up tennis scattered on a court after training becomes heavy physical labor, and the cost of hiring a child is high, so that the tennis training is difficult to be widely accepted by the masses. The traditional ball picking basket needs manual pulling operation, and has low efficiency. The friction type ball picking device has high noise, and tennis balls are easy to collide with the ball storage device strongly. The suction type ball picking device has high power, high noise and easy suction of sundries, and the impeller type ball picking device has easy ball clamping problem. The mechanical claw type ball picking device can pick up only one tennis ball at a time and has high requirement on positioning precision. The part of intelligent ball picking vehicles lack the function of automatically identifying tennis balls, manual remote control is needed, and the intelligent degree is low. Disclosure of Invention In view of the above, the invention aims to provide a tennis receiving and dispatching intelligent vehicle based on machine vision and a working method thereof, which realize the automation of the whole process of identification, pickup, movement and ball serving in training. The invention adopts the following technical scheme that the tennis receiving and dispatching intelligent vehicle based on machine vision comprises a machine body frame, a visual identification module, an automatic pickup module, a motion control module, an intelligent service module, an upper computer and a lower computer, wherein the modules are integrated on the machine body frame, the upper computer is in communication connection with the lower computer through a serial port, the upper computer realizes image processing and motion planning, and the lower computer realizes motion control, wherein: the visual recognition module comprises image acquisition equipment, a monocular visual recognition unit and a binocular visual recognition unit, wherein the monocular visual recognition unit comprises a CMOS camera corresponding to the CMOS camera; the binocular vision recognition unit comprises two CMOS cameras which are symmetrically distributed and construct a stereoscopic shooting structure, wherein the monocular vision recognition unit comprises a recognition algorithm based on HSV color characteristics, and the binocular vision recognition unit comprises a stereoscopic vision algorithm based on contour and height information; the automatic pickup module comprises a driving roller, a conveyor belt, a flexible baffle, a lifting plate, a ball storage basket, a ball guide plate, a tensioning device and a profile frame, wherein the surface of the conveyor belt is provided with a roller O-shaped groove and a guide bar, the driving roller is in transmission connection with the conveyor belt, the flexible baffle is fixed on one side of the input end of the conveyor belt, the lifting plate is obliquely arranged, the lower end of the lifting plate is connected with the conveyor belt, the upper end of the lifting plate extends to the inlet of the ball storage basket, the ball guide plate is arranged on the top of the conveyor belt and bends towards one side of the ball storage basket, the tensioning device is matched with the conveyor belt, and the profile frame is fixedly connected with the frame of the machine body; The motion control module comprises a crawler-type differential chassis, a microcontroller, a positioning system, a motor and a driver, wherein the crawler-type differential chassis comprises a left crawler belt, a right crawler belt and corresponding driving wheels, the motor is electrically connected with the driver and is in transmission fit with the driving wheels, and the microcontroller is respectively electrically connected with the positioning system and the driver; the intelligent pitching module comprises double friction wheels, a pitch angle adjusting mechanism, a horizontal angle adjusting mechanism and a stepping motor, wherein the double friction wheels are arranged at intervals in parallel, the stepping motor is respectively connected with the pitch angle adjusting mechanism and the horizontal angle adjusting mechanism in a transmission manner, the pitch angle adjusting mechanism is hinged with a mounting frame of the double friction wheels, and the horizontal angle adjusting mechanism is connected with a fixing seat of the pitc