Automatic guided vehicle charging system

Abstract

The invention discloses an automatic guided vehicle charging system, which starts detection after an automatic guided vehicle enters a charging area and drives away from the charging area after the automatic guided vehicle is charged, and comprises charging position detection and charging device connection. The charging position detection comprises image processing, noise reduction processing and ellipse fitting, so that the insertion accuracy of a charging wiping plug is ensured; the charging device comprises a charging plug and a charging pile, the charging plug is fixed to the tail end of the mechanical arm, the charging pile is fixed to the automatic guide trolley body, an elastic device is arranged on the mechanical structure aspect, the fault tolerance rate of connection of the charging device is increased, and the feasibility of connection of the charging device is ensured. Through the combined design of the detection system and the mechanical device, the charging function of the automated guided vehicle is realized, the battery replacement operation of the automated guided vehicle is avoided, the continuity and smoothness of work are ensured, and the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to an automatic guided vehicle charging technology, in particular to an automatic guided vehicle charging system. Background Art

[0002] The Automated Guided Vehicle is a new type of mobile robot and an important tool in modern logistics systems. It is used in automated warehouses and flexible storage systems, and plays an important role in industrial production and storage and handling, making production more flexible. The Automated Guided Vehicle is mainly composed of a power supply and charging device, a control module, a safety device, a guidance module, a travel drive device, etc.

[0003] The battery is the power source of the automatic guided vehicle, providing energy for the realization of various functions of the automatic guided vehicle. Due to the limitation of battery capacity, when the remaining power of the battery is lower than the safety threshold, the automatic guided vehicle may stop working. The limited battery power requires the vehicle to be charged regularly to meet the energy replenishment. The current charging methods can be divided into three categories: manual charging, automatic charging and battery replacement charging. Manual charging and battery replacement charging methods have a low degree of automation and are only suitable for places with special needs. For automatic charging, most of the existing mobile robot charging devices have fixed charging input and output terminals, and the positioning accuracy requirements are very high. After moving to a certain range of the charging position, it is necessary to continuously move closer to the charging pile according to the sensor information, which is time-consuming and laborious. Moreover, the connection of the charging device almost relies on the redundant sensor information of the AGV body to realize the identification of the charging position. From the perspective of the amount of information, the processed information is too complex and the amount of data is large, which leads to too much time spent in finding the charging position and low charging efficiency. Summary of the invention

[0004] In order to solve the problems of the prior art, the present invention provides an automatic guided vehicle charging system, which starts detection after the automatic guided vehicle enters the charging area, and leaves the charging area after the automatic guided vehicle completes charging, including charging position detection and charging device connection. Charging position detection includes image processing, Ransac algorithm iteration and ellipse fitting to ensure the accuracy of the charging plug insertion; the charging device includes a charging plug and a charging pile, the charging plug is fixed to the end of the manipulator, and the charging pile is fixed to the automatic guided vehicle body. In terms of mechanical structure, there are elastic devices, which improve the fault tolerance of the charging device connection, ensure the feasibility of the charging device connection, and consider the installability and replaceability, reducing the installation cost and replacement cost. The present invention realizes the charging function of the automatic guided vehicle through the joint design of the detection system and the mechanical device, avoids the battery replacement operation of the automatic guided vehicle, ensures the continuity and smoothness of the work, and improves production efficiency.

[0005] The solution adopted by the present invention to solve its technical problems is: an automatic guided vehicle charging system, including a charging position detection device, a charging pile and a charging plug device: during charging, the charging position detection device obtains image information and detects the charging port position information, and the charging plug device moves to the charging pile interface for coupling to complete the charging of the automatic guided vehicle.

[0006] Specifically, the charging position detection device includes an image sensor and a target recognition device. The image sensor is placed in a fixed area above the charging area, perpendicular to the ground, and receives image information of the charging area in real time. The target recognition device obtains the image information returned by the image sensor, performs image processing, and performs noise reduction and shape fitting on the edge points of the charging port obtained by the image processing to obtain the charging port position information. The image processing includes: Convert the received RGB image frame into the HSV color space to obtain an HSV image; Separate the channels of the HSV image, perform histogram equalization on each channel, and merge the equalized channels; Set the threshold to perform color image segmentation on the image after histogram equalization; Eliminate noise points and connect connected domains through opening and closing operations; The edge point set of the charging port is obtained through contour detection and parent-child contour relationship.

[0007] The noise reduction and shape fitting include RANSAC algorithm iteration and ellipse fitting. The RANSAC algorithm iteration randomly selects a certain number of the edge points of the charging port for ellipse fitting to obtain the general equation of the ellipse. According to the obtained ellipse equation, the algebraic distance between the edge points of the charging port excluding the selected points and the ellipse is calculated to determine whether the distance is less than a threshold. If it is less than, it is an "in-place point", and if it is greater than, it is an "out-of-place point". After multiple iterations, when the maximum number of iterations is reached, the ellipse equation with the largest number of in-place points is output. The ellipse fitting adopts direct least squares fitting. After the noise reduction process, the disadvantage that the least squares method cannot exclude abnormal points is compensated. The selected points are directly fitted by the least squares method to obtain the general equation of the ellipse. The charging port position information is obtained through the relationship between the geometric position information of the ellipse and the general equation.

[0008] The charging pile includes a left base, a right base and a charging pile elastic device. The left base and the right base are split from the main base, and are symmetrical about the joint surface in appearance. The two bases are connected by four bolts and nuts. The main base is fixed to the automatic guided vehicle and connected to the automatic guided vehicle power module. The main base is hollow inside, and the positive charging pile elastic device and the negative charging pile elastic device are installed from top to bottom. The upper interface of the main base is a cone, the upper interface of the cone is elliptical, and the lower interface is circular.

[0009] The charging pile elastic device includes a movable block and a spring. The movable block and the spring are installed in the positive and negative lead areas of the base. The movable block is hollow inside, and the lead passes through the inside to connect with the electrode sheet. The joint between the movable block and the electrode sheet is designed to be a combination of an inclined surface and a flat surface, which is convenient for the charging plug to be inserted. The spring is a compression spring to ensure the tight connection of the electrode sheet.

[0010] The charging plug device includes a flange, a radial elastic device, a deformation partition device, an axial elastic device, a guide head-body, a guide head-head and an electrode sheet. The upper end of the flange is connected to the mechanical arm, and the lower end is connected to the radial elastic device. The upper part of the deformation partition device is sleeved with the radial elastic device, and the lower part is sleeved with the axial elastic device. The lower part of the axial elastic device is sleeved with the guide head-body, and the guide head-body is connected to the guide head-head by threads. There are accommodating grooves on both sides of the guide head-body for placing the electrode sheet, and a hole is opened in the middle of the accommodating groove for connecting the wire to the electrode sheet.

[0011] The charging plug radial elastic device and the axial elastic device include an internal spring and an external universal telescopic tube. One end of the universal telescopic tube is sleeved with the deformation partition device, and the other end is connected to the flange or the guide head-body.

[0012] The present invention realizes the charging function of the automatic guided vehicle by the joint design of the detection system and the mechanical device. The detection system identifies the shape of the charging port and obtains the position information of the charging port. The mechanical device ensures the close connection between the electrode sheets, thereby avoiding the manual charging of the automatic guided vehicle and the battery replacement operation. At the same time, the design of the elastic device makes the charging device have a larger fault tolerance rate, ensures the continuity and smoothness of the work, and improves the production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is the overall framework diagram of the automatic guided vehicle charging system.

[0014] FIG2 is a schematic diagram of each stage of image processing of an automatic guided vehicle charging system; Figure 2a is the original RGB image obtained, Figure 2b is the image converted to HSV space and histogram equalized. Figure 2c It is the result after color image segmentation and morphological processing. Figure 2d It is the result after denoising and fitting.

[0015] Figure 3 Front planing view of the automatic guided vehicle charging system.

[0016] Figure 4This is a top view of the automatic guided vehicle charging system.

[0017] Figure 5 This is a front plan view of the charging pile.

[0018] Figure 6 This is a planed view of the front of the charging plug. Implementation

[0019] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0020] like Figure 1 As shown, the present invention provides an automatic guided vehicle charging system, which starts detection after the automatic guided vehicle enters the charging area, and leaves the charging area after the automatic guided vehicle completes charging, including a charging position detection device 100 and a charging connection device 200. The charging position detection device includes an image processing module 300, a noise reduction processing module 400 and an ellipse fitting module 500 to ensure the accuracy of the charging plug insertion; the charging connection device 200 includes a charging plug I and a charging pile II, the charging plug is fixed to the end of the manipulator, and the charging pile is fixed to the automatic guided vehicle body. In terms of mechanical structure, there are elastic devices, which improve the fault tolerance of the charging device connection and ensure the feasibility of the charging device connection.

[0021] The patent of the present invention includes a charging position detection device 100, a charging pile I and a charging plug device II: during charging, the charging position detection device 100 obtains image information and detects the position information of the charging port, and the charging plug device I moves to the interface of the charging pile II for coupling to complete the charging of the automatic guided vehicle.

[0022] Specifically, the charging position detection device 100 includes an image sensor and a target recognition device. The image sensor is placed in a fixed area above the charging area, perpendicular to the ground, and receives image information of the charging area in real time. The target recognition device obtains the image information sent back by the image sensor, performs image processing, and performs noise reduction and shape fitting on the edge points of the charging port obtained by the image processing to obtain the charging port position information. As shown in FIG. 2 , the image processing 3 includes: Convert the received RGB image frame into the HSV color space to obtain an HSV image; Separate the channels of the HSV image, perform histogram equalization on each channel, and merge the equalized channels; Set the threshold to perform color image segmentation on the image after histogram equalization; Eliminate noise points and connect connected domains through opening and closing operations; The edge point set of the charging port is obtained through contour detection and parent-child contour relationship.

[0023] The noise reduction and shape fitting include RANSAC algorithm iteration and ellipse fitting. The RANSAC algorithm iteration randomly selects a certain number of the edge points of the charging port for ellipse fitting to obtain the general equation of the ellipse. According to the obtained ellipse equation, the algebraic distance between the edge points of the charging port excluding the selected points and the ellipse is calculated to determine whether the distance is less than a threshold. If it is less than, it is an "in-place point", and if it is greater than, it is an "out-of-place point". After multiple iterations, when the maximum number of iterations is reached, the ellipse equation with the largest number of in-place points is output. The ellipse fitting adopts direct least squares fitting. After the noise reduction process, the disadvantage that the least squares method cannot exclude abnormal points is compensated. The selected points are directly fitted by the least squares method to obtain the general equation of the ellipse. The charging port position information is obtained through the relationship between the geometric position information of the ellipse and the general equation.

[0024] like Figure 3 and Figure 4 As shown, the charging connection device 200 includes a charging plug I and a charging pile II.

[0025] like Figure 5 As shown, the charging pile I includes a left base 3, a right base 16 and a charging pile elastic device. The left base 3 and the right base 16 are split from the main base and are symmetrical about the joint surface in appearance. The two bases are connected by four bolts 4 and nuts 14. The main base is fixed to the automatic guided vehicle and connected to the automatic guided vehicle power module. The main base is hollow inside, and the positive charging pile elastic device and the negative charging pile elastic device are installed from top to bottom. The upper interface of the main base is a cone, the upper interface of the cone is elliptical, and the lower interface is circular.

[0026] The charging pile elastic device includes a movable block 2 and a spring 1. The movable block 2 and the spring 1 are installed in the positive wire area and the negative wire area of ​​the base. The movable block 2 is hollow inside, and the wire passes through the inside to connect with the electrode sheet. The joint between the movable block 2 and the electrode sheet is designed to be a combination of an inclined surface and a flat surface, which is convenient for the charging plug to be inserted. The spring 1 is a compression spring to ensure the tight connection of the electrode sheet.

[0027] like Figure 6As shown, the charging plug II device includes a flange 10, a radial elastic device, a deformation partition device 7, an axial elastic device, a guide head-body 11, a guide head-head 13 and an electrode sheet. The upper end of the flange 10 is connected to the mechanical arm, and the lower end is connected to the radial elastic device. The upper part of the deformation partition device 7 is sleeved with the radial elastic device, and the lower part is sleeved with the axial elastic device. The lower part of the axial elastic device is sleeved with the guide head-body 11, and the guide head-body 11 is connected to the guide head-head 13 by threads. There are accommodating grooves on both sides of the guide head-body 11 for placing the electrode sheet, and a hole is opened in the middle of the accommodating groove for connecting the wire to the electrode sheet.

[0028] The charging plug radial elastic device and the axial elastic device include an internal spring 5 and an external universal telescopic tube 6. One end of the universal telescopic tube is sleeved with the deformation isolation device 7, and the other end is connected to the flange 10 or the guide head-body 11.

Claims

1. An automatic guided vehicle charging system, characterized in that: It includes a charging position detection device, a charging pile and a charging plug device. When charging, the charging position detection device obtains image information and detects the position information of the charging port. The charging plug device moves to the charging pile interface for coupling to complete the charging of the automatic guided vehicle.

2. The automatic guided vehicle charging system according to claim 1, characterized in that: The charging position detection device includes an image sensor and a target recognition device. The image sensor is placed in a fixed area above the charging area, perpendicular to the ground, and receives image information of the charging area in real time. The target recognition device obtains the image information sent back by the image sensor, performs image processing, and performs noise reduction and shape fitting on the edge points of the charging port obtained by the image processing to obtain the charging port position information. The image processing comprises: Convert the received RGB image frame into the HSV color space to obtain an HSV image; Separate the channels of the HSV image, perform histogram equalization on each channel, and merge the equalized channels; Set the threshold to perform color image segmentation on the image after histogram equalization; Eliminate noise points and connect connected domains through opening and closing operations; The edge point set of the charging port is obtained through contour detection and parent-child contour relationship.

3. The automatic guided vehicle charging system according to claim 2, characterized in that: The noise reduction and shape fitting include RANSAC algorithm iteration and ellipse fitting. The RANSAC algorithm iteration randomly selects a certain number of the edge points of the charging port for ellipse fitting to obtain a general equation of the ellipse. According to the obtained ellipse equation, the algebraic distance between the edge points of the charging port excluding the selected points and the ellipse is calculated to determine whether the distance is less than a threshold. If it is less than, it is an "in-place point", and if it is greater than, it is an "out-of-place point". After multiple iterations, when the maximum number of iterations is reached, the ellipse equation with the largest number of in-place points is output. The ellipse fitting adopts direct least squares fitting. After the noise reduction processing, the disadvantage that the least squares method cannot exclude abnormal points is compensated. The selected points are directly fitted by the least squares method to obtain the general equation of the ellipse. The charging port position information is obtained through the relationship between the geometric position information of the ellipse and the general equation.

4. The automatic guided vehicle charging system according to any one of claims 1 to 3, characterized in that: The charging pile includes a left base, a right base and a charging pile elastic device. The left base and the right base are split from the main base, and are symmetrical about the joint surface in appearance. The two bases are connected by four bolts and nuts. The main base is fixed to the automatic guided vehicle and connected to the automatic guided vehicle power module. The main base is hollow inside, and the positive charging pile elastic device and the negative charging pile elastic device are installed from top to bottom. The upper interface of the main base is a cone, the upper interface of the cone is elliptical, and the lower interface is circular.

5. The automatic guided vehicle charging system according to claim 1 or 4, characterized in that: The charging pile elastic device includes a movable block and a spring, which are installed in the positive wire area and the negative wire area of ​​the base. The movable block is hollow inside, and the wire passes through the inside to connect with the electrode sheet. The joint between the movable block and the electrode sheet is designed as a combination of an inclined surface and a plane to facilitate the insertion of the charging plug. The spring is a compression spring to ensure the tight connection of the electrode sheet.

6. The automatic guided vehicle charging system according to any one of claims 1 or 5, characterized in that: The charging plug device includes a flange, a radial elastic device, a deformation partition device, an axial elastic device, a guide head-body, a guide head-head and an electrode sheet. The upper end of the flange is connected to the mechanical arm, and the lower end is connected to the radial elastic device. The upper part of the deformation partition device is sleeved with the radial elastic device, and the lower part is sleeved with the axial elastic device. The lower part of the axial elastic device is sleeved with the guide head-body. The guide head-body is connected to the guide head-head through threads. There are accommodating grooves on both sides of the guide head-body for placing the electrode sheet, and a hole is opened in the middle of the accommodating groove for connecting the wire to the electrode sheet.

7. The automatic guided vehicle charging system according to claim 6, characterized in that: The radial elastic device of the charging plug and the axial elastic device include an internal spring and an external universal telescopic tube. One end of the universal telescopic tube is sleeved with the deformation partition device, and the other end is connected to the flange or the guide head-body.

Images