An automatic alignment structure and method for AGV charging port

Abstract

The present invention relates to an automatic alignment structure and method for an AGV charging port, comprising a charging pile track, an AGV track and a measuring component, wherein the charging pile track and the AGV track are both made of conductive materials and are arranged in parallel; the measuring component comprises an AC signal source, a resistor R, an inductor L and an ammeter connected in series in sequence; the AC signal source and the ammeter each lead out a wire and are electrically connected to the charging pile track and the AGV track respectively; the ammeter is electrically connected to a single-chip computer; a charging pile is provided on the charging pile track; the charging pile is provided with a first flat plate electrode electrically connected to the charging pile track; the AGV is provided with a second flat plate electrode, and when the AGV track moves, the second flat plate electrode is electrically connected to the AGV track. The single-chip computer continuously collects the ammeter values ​​and forms a series; the series is then fitted into a curve and derived; when the derivative sign changes, the charging port of the AGV is aligned with the charging port of the charging pile.

Description

Technical Field

[0001] The present invention relates to an automatic control structure and method, in particular to a structure and method applied to AGV charging, specifically to an AGV charging port automatic alignment structure and method. Background Art

[0002] AGV (Automated Guided Vehicle) plays an important role in automated logistics and unmanned production. It is of great significance to improve work efficiency, optimize inventory management, automate sorting, realize automatic guidance and navigation, and collect and analyze data. When the AGV battery level drops below the warning value, it needs to be automatically charged. During the automatic charging process of the AGV, how to accurately align it with the charging port is a technical problem.

[0003] There are two main methods currently used in practice:

[0004] 1) Visual alignment: Visual alignment requires the AGV to use a camera to collect images and analyze signs or specific landmarks in the environment to enable the robot to accurately locate the charging station and automatically navigate to the location of the charging station. This method is low-cost, but it is easily affected by light interference, which affects the use effect.

[0005] 2) Laser alignment: Laser alignment requires the AGV to install a laser radar to scan the surrounding environment and determine its relative position to the charging station by comparing the pre-stored map information. This method has high accuracy, but the cost is also high, which is not conducive to promotion.

[0006] Therefore, it is urgently needed to be improved in order to better meet the market demand. Summary of the invention

[0007] The purpose of the present invention is to provide an AGV charging port automatic alignment structure and method to address the deficiencies in the prior art, so that the AGV can be quickly and accurately aligned with the charging port of a charging pile. Moreover, the structure is simple, the cost is low, the control is convenient, and it is conducive to promotion and use.

[0008] The technical solution of the present invention is:

[0009] An automatic alignment structure for an AGV charging port, comprising a charging pile track, an AGV track and a measuring component, wherein the charging pile track and the AGV track are both made of conductive materials and are arranged in parallel with each other; the measuring component comprises an AC signal source, a resistor R, an inductor L and an ammeter connected in series in sequence; the AC signal source and the ammeter are electrically connected to the charging pile track and the AGV track respectively; the ammeter is electrically connected to a single-chip computer;

[0010] A charging pile is provided on the charging pile track; the AGV track can allow the AGV to travel; a first flat electrode is provided on the charging pile; the first flat electrode is electrically connected to the charging pile track; a second flat electrode is provided on the AGV; when the AGV is located on the AGV track, the second flat electrode is electrically connected to the AGV track; the first flat electrode and the second flat electrode have the same shape and size and are at the same height; when the first flat electrode is facing the second flat electrode, the charging port of the AGV is aligned with the charging port of the charging pile.

[0011] Furthermore, the charging pile track and the AGV track are both linear.

[0012] Furthermore, when the first flat electrode and the second flat electrode are facing each other, the distance therebetween is ≤5 cm.

[0013] Furthermore, the ammeter is connected to the single chip microcomputer via an RS232 communication line.

[0014] Furthermore, there are multiple charging piles.

[0015] An AGV charging port automatic alignment method, using the above-mentioned AGV charging port automatic alignment structure, comprises the following steps:

[0016] 1) A charging pile is set on the charging pile track; the AGV enters the AGV track and moves at a constant speed along the AGV track; at the same time, the single-chip microcomputer continuously collects the current value of the ammeter in a cycle, and the sampling period is T;

[0017] 2) When the current value suddenly starts to rise from a constant value, the microcontroller starts to record the current current value as i0, and the current moment is recorded as 0;

[0018] 3) Collect current values ​​every T time to form a sequence {i n}=i0,i1,i2...i n ;

[0019] 4) Logarithmic sequence {i n} Perform quadratic polynomial fitting to obtain the relationship curve between current and time i(t), where t represents time;

[0020] 5) Derivative the curve i(t), and calculate the derivative at the current moment and the derivative at the previous moment to determine whether the two have opposite signs; if the signs are opposite, it indicates that the charging port of the AGV is exactly aligned with the charging port of the charging pile, then an instruction is immediately issued to stop the AGV from moving along the AGV track, detach from the AGV track, and dock with the charging pile to achieve charging.

[0021] Furthermore, in step 1), the sampling period T is 20 ms.

[0022] Furthermore, in the step 1), N charging piles are arranged on the charging pile track, and N≥2; at the same time, a counting function is set in the single chip microcomputer; in the step 5), when the derivative of the curve i(t) has a reverse sign for the first time, the AGV does not stop moving until the derivative of the curve i(t) has a reverse sign for the Nth time, the AGV stops moving along the AGV track and leaves the AGV track for charging; at the same time, the single chip microcomputer sets N-1; then, the second AGV repeats steps 1) to step 5); and the cycle continues until N is 0.

[0023] Furthermore, each of the AGVs enters the AGV track from the same end of the AGV track and moves in the same direction.

[0024] Beneficial effects of the present invention:

[0025] The present invention has reasonable design and convenient operation, and can enable the AGV to be quickly and accurately aligned with the charging port of the charging pile. Moreover, it has a simple structure, low cost, good robustness, is easy to use and promote, and fully meets market demand. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structural principle of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0028] like Figure 1 As shown, an AGV charging port automatic alignment structure of the present invention includes a charging pile track, an AGV track and a measuring component.

[0029] The charging pile track and the AGV track are both linear and arranged parallel to each other. At the same time, the charging pile track and the AGV track are both made of conductive materials.

[0030] The measuring component includes an AC signal source, a resistor R, an inductor L and an ammeter connected in series in sequence, and the AC signal source and the ammeter each lead out a wire and are electrically connected to the charging pile track and the AGV track respectively, so that the charging pile track, the measuring component and the AGV track form a conductive path. The ammeter is also connected to a single-chip microcomputer via an RS232 communication line, and the value of the ammeter can be monitored by the single-chip microcomputer.

[0031] One or more charging piles are arranged on the charging pile track. Each charging pile is provided with a first flat plate electrode. The first flat plate electrode is electrically connected to the charging pile track.

[0032] The AGV track can be used for the AGV to travel. Meanwhile, a second flat plate electrode is provided on the AGV, and when the AGV is located on the AGV track, the second flat plate electrode is electrically connected to the AGV track.

[0033] The first flat electrode and the second flat electrode have the same shape and size and are at the same height. When the AGV moves along the AGV track until the first flat electrode is directly opposite to the second flat electrode, the charging port of the AGV can be completely aligned with the charging port of the charging pile.

[0034] In order to ensure the use effect, when the first flat electrode and the second flat electrode are facing each other, the distance between them is ≤5cm.

[0035] Preferably, the effective value of the signal source is 24V, the waveform is a sine wave, and the frequency is 100MHz. The size of the first flat electrode and the second flat electrode are both 0.2m×0.2m. The resistor R is 24MΩ. The inductor L is 36mH.

[0036] The present invention provides an automatic alignment method for an AGV charging port, which adopts the above-mentioned automatic alignment structure for an AGV charging port, and includes the following two embodiments.

[0037] Embodiment 1 comprises the following steps:

[0038] 1) There is a charging pile on the charging pile track; the AGV enters the AGV track and moves at a constant speed along the AGV track; at the same time, the single-chip microcomputer continuously collects the current value of the ammeter in a cycle, and the sampling period is T; T is 20ms;

[0039] 2) When the current value suddenly starts to rise from a constant value, it means that the electrodes overlap, forming a capacitor and there is current in the track; at this time, the microcontroller starts to record the current current value as i0, and the current moment is recorded as 0;

[0040] 3) Collect current values ​​every T time to form a sequence {i n}=i0,i1,i2...i n ;

[0041] 4) Fit the sequence {in} with a quadratic polynomial to obtain the relationship curve between current and time i(t), where t represents time;

[0042] 5) Derivative the curve i(t), and calculate the derivative at the current moment and the derivative at the previous moment, and determine whether the two have opposite signs; if the signs are opposite, it means that the current moment has exceeded the extreme point of the curve, that is, the area facing each other of the two flat electrodes has reached the maximum and has a tendency to decrease; therefore, at this moment, the AGV charging port is exactly aligned with the charging port of the charging pile; and the single-chip microcomputer immediately sends a command to stop the AGV from moving along the AGV track, and leave the AGV track, and approach the charging pile to achieve charging.

[0043] Embodiment 2 comprises the following steps:

[0044] 1) There are N charging piles on the charging pile track, and N ≥ 2; at the same time, a counting function is set in the single chip microcomputer;

[0045] The first AGV enters the AGV track and moves at a constant speed along the AGV track. At the same time, the single-chip microcomputer continuously collects the current value of the ammeter in a cycle, and the sampling period is T; T is 20ms.

[0046] 2) When the current value suddenly starts to rise from a constant value, the microcontroller starts to record the current current value as i0, and the current moment is recorded as 0;

[0047] 3) Collect current values ​​every T time to form a sequence {i n}=i0,i1,i2...i n ;

[0048] 4) Logarithmic sequence {i n} Perform quadratic polynomial fitting to obtain the relationship curve between current and time i(t), where t represents time;

[0049] 5) Derivative the curve i(t), and calculate the derivative at the current moment and the derivative at the previous moment, and determine whether the signs of the two are opposite;

[0050] When the derivative of the curve i(t) has an opposite sign for the first time, the AGV does not stop moving until the derivative of the curve i(t) has an opposite sign for the Nth time. The AGV stops moving along the AGV track, leaves the AGV track, and moves toward the charging pile for charging. At the same time, the microcontroller sets N-1; then, the second AGV repeats steps 1) to 5); and the cycle continues until N is 0.

[0051] In the second embodiment, all AGVs enter the AGV track from the same end and move along the same direction on the AGV track, so that multiple AGVs can automatically align with the charging piles to improve efficiency.

[0052] The present invention can enable the AGV to be quickly and accurately aligned with the charging port of the charging pile, and has a simple structure, low cost, good robustness, and is easy to use and promote, thus fully meeting market demand.

[0053] The parts not involved in the present invention are the same as the prior art or can be implemented by using the prior art.

Claims

1. An automatic alignment method for an AGV charging port, characterized in that: It includes a charging pile track, an AGV track and a measuring component, wherein the charging pile track and the AGV track are both made of conductive materials and are arranged in parallel with each other; the measuring component includes an AC signal source, a resistor R, an inductor L and an ammeter connected in series in sequence; the AC signal source and the ammeter are electrically connected to the charging pile track and the AGV track respectively; the ammeter is electrically connected to the single-chip computer; The charging pile track is provided with a charging pile; the AGV track can be used for the AGV to travel; the charging pile is provided with a first flat electrode; the first flat electrode is electrically connected to the charging pile track; the AGV is provided with a second flat electrode; when the AGV is located on the AGV track, the second flat electrode is electrically connected to the AGV track; the first flat electrode and the second flat electrode have the same shape and size and are at the same height; when the first flat electrode is facing the second flat electrode, the charging port of the AGV is aligned with the charging port of the charging pile; The AGV charging port automatic alignment method comprises the following steps: 1) A charging pile is set on the charging pile track; the AGV enters the AGV track and moves at a constant speed along the AGV track; at the same time, the single-chip microcomputer continuously collects the current value of the ammeter, and the sampling period is T; 2) When the current value suddenly starts to rise from a constant value, the microcontroller starts to record the current current value as i0, and the current moment is recorded as 0; 3) Collect current values ​​every T time to form a sequence {i n }=i0,i1,i2...i n ; 4) Logarithmic sequence {i n } Perform quadratic polynomial fitting to obtain the relationship curve between current and time i(t), where t represents time; 5) Derivative the curve i(t), and calculate the derivative at the current moment and the derivative at the previous moment to determine whether the two have opposite signs; if the signs are opposite, it means that the charging port of the AGV is exactly aligned with the charging port of the charging pile at this time, then an instruction is immediately issued to stop the AGV from moving along the AGV track, detach from the AGV track, and dock with the charging pile to achieve charging.

2. The AGV charging port automatic alignment method according to claim 1 is characterized in that: The charging pile track and the AGV track are both linear.

3. The AGV charging port automatic alignment method according to claim 1 is characterized in that: When the first flat electrode and the second flat electrode face each other, the distance between them is ≤5 cm.

4. The AGV charging port automatic alignment method according to claim 1 is characterized in that: The ammeter is connected to the single chip microcomputer via an RS232 communication line.

5. The AGV charging port automatic alignment method according to claim 1 is characterized in that: There are multiple charging piles.

6. The AGV charging port automatic alignment method according to claim 1 is characterized in that: In the step 1), the sampling period T is 20 ms.

7. The AGV charging port automatic alignment method according to claim 1 is characterized in that: In the step 1), N charging piles are arranged on the charging pile track, and N≥2; at the same time, a counting function is set in the single chip microcomputer; in the step 5), when the derivative of the curve i(t) has a reverse sign for the first time, the AGV does not stop moving until the derivative of the curve i(t) has a reverse sign for the Nth time, the AGV stops moving along the AGV track and leaves the AGV track for charging; at the same time, the single chip microcomputer sets N-1; then, the second AGV repeats steps 1) to 5); and the cycle continues until N is 0.

8. The AGV charging port automatic alignment method according to claim 7 is characterized in that: Each of the AGVs enters the AGV track from the same end of the AGV track and moves in the same direction.

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