AGV transverse movement deviation correction method and device

Abstract

The invention relates to the technical field of AGV navigation, in particular to an AGV transverse movement deviation correction method and device.The method comprises the steps that in the transverse movement process, firstly, the travelled distance of a front differential module and the travelled distance of a rear differential module are calibrated through a polarity sensor, and the mileage difference value between the front differential module and the rear differential module is obtained; carrying out arcsine operation based on the mileage difference value and the distance between the driving wheels so as to obtain a real-time deflection angle of the AGV; then the real-time deflection angle serves as input of a PI controller, and the adjusting speed output by the PI controller is obtained; and finally, combining the adjusting speed with the reference speed of the AGV to obtain a target speed, and controlling the AGV to transversely move according to the target speed. According to the method, the mileage calibration is mainly adopted, so that the long-distance transverse moving precision of the AGV with the long vehicle body length is remarkably improved, transverse moving is not affected by the speed, the whole process from transverse moving starting to transverse moving ending is corrected in real time, and the transverse moving stability is improved.

Description

Technical Field

[0001] The present invention relates to the field of AGV navigation technology, and in particular to an AGV lateral movement correction method and device. Background Art

[0002] In the use environment of AGV (Automated Guided Vehicle), it is often necessary to dock with various equipment to complete material transportation, assembly or other operations. Due to the limitations of the on-site layout, sometimes the AGV cannot directly dock with the equipment in a straight line. At this time, it is necessary to perform a lateral movement operation, that is, the AGV moves horizontally while maintaining a certain speed.

[0003] For lateral movement operations, if the deviation is too large, the AGV will not be able to accurately dock at the position where it is docked with the equipment, thus affecting work efficiency and safety, so the accuracy requirements are often very high. However, the traditional gyroscope-based lateral movement control method has obvious limitations. When the AGV body length is long (more than 4 meters), the angular velocity change rate generated during the lateral movement is relatively small. In this case, the gyroscope may not be able to accurately identify this tiny angular velocity change, resulting in a deviation in lateral movement control. As the lateral movement distance increases, this deviation will gradually accumulate, eventually resulting in the AGV body angle being too large at the end of the lateral movement, and unable to complete the precise docking with the equipment.

[0004] Therefore, for AGVs with a long body length, the lateral movement accuracy of the traditional gyroscope-based lateral movement control method often cannot meet actual needs. Summary of the invention

[0005] In view of this, the present invention provides an AGV lateral movement correction method and device to solve the problem that when the body length of the AGV is long, if a gyroscope-based lateral movement control method is used, its lateral movement accuracy often cannot meet actual needs.

[0006] In a first aspect, the present invention provides an AGV lateral deviation correction method, the method is applied to the AGV, the AGV is equipped with a front polarity sensor, a rear polarity sensor, a front differential module and a rear differential module, the method comprises:

[0007] During the lateral movement, the mileage of the front differential module and the rear differential module are calibrated respectively by the front polarity sensor and the rear polarity sensor, and the mileage difference between the front differential module and the rear differential module is obtained;

[0008] Obtaining a distance between the front differential module and the rear differential module;

[0009] Performing an arcsine operation based on the mileage difference and the distance to obtain a real-time deflection angle of the AGV;

[0010] Using the real-time deflection angle as an input of a PI controller, and obtaining a regulating speed output by the PI controller;

[0011] The adjustment speed is combined with the reference speed of the AGV to obtain a target speed, and the AGV is controlled to perform lateral movement according to the target speed.

[0012] The above scheme of the present invention uses the front polarity sensor and the rear polarity sensor to calibrate the mileage of the front differential module and the rear differential module in real time, effectively reducing the cumulative error caused by long-distance driving, thereby improving the accuracy during the lateral movement. In addition, the mileage difference and spacing between the front differential module and the rear differential module are used to accurately calculate the real-time deflection angle of the AGV through inverse sine operation, so that the AGV can adjust its posture in real time to ensure the accuracy of the lateral movement path.

[0013] In an optional implementation, the differential module is further provided with a rotary encoder, and before performing the lateral movement, the method further includes:

[0014] Receiving a lateral movement instruction, and respectively obtaining an initial angle of a front driving wheel and an initial angle of a rear driving wheel of the AGV through the rotary encoder;

[0015] The initial angles of the front driving wheels and the rear driving wheels are adjusted to target angles, and a lateral movement is performed.

[0016] In an optional embodiment, a corresponding polarity magnetic strip is provided at each target distance interval on the lateral movement path of the AGV, and the polarity sensor is used to read the polarity magnetic strip on the lateral movement path to calibrate the mileage of each differential module obtained by the motor encoder;

[0017] Each time the polarity sensor reads the polarity magnetic stripe, it represents that the mileage of the corresponding differential module increases by the target distance.

[0018] In an optional implementation, the obtaining the mileage difference between the front differential module and the rear differential module includes:

[0019] Respectively obtaining the front mileage of the front differential module and the rear mileage of the rear differential module;

[0020] A difference calculation is performed based on the front mileage and the rear mileage to obtain a mileage difference between the front differential module and the rear differential module.

[0021] In an optional implementation, the taking the real-time deflection angle as an input of a PI controller and obtaining a regulation speed output by the PI controller includes:

[0022] The real-time deflection angle is converted into radians and input into the PI controller for proportional and integral regulation to obtain the regulation speed output by the PI controller.

[0023] In an optional embodiment, combining the adjustment speed with the reference speed of the AGV to obtain a target speed includes:

[0024] Adding or subtracting the adjustment speed from the reference speed of the AGV to obtain a target speed of each differential module;

[0025] The target speed conversion is unit-converted and sent to a control unit of a corresponding differential module.

[0026] In an optional embodiment, the method further includes:

[0027] During the lateral movement, the operating angle of the AGV is monitored in real time by the rotary encoder, and when the operating angle of the AGV exceeds a set range, an alarm message is output.

[0028] In an optional embodiment, the method further includes:

[0029] At the end of the traverse operation of the AGV, the integral term of the PI controller is reset to zero.

[0030] In a second aspect, the present invention provides an AGV lateral deviation correction device, which is applied to the AGV, and the AGV is equipped with a front polarity sensor, a rear polarity sensor, a front differential module and a rear differential module, and the device includes:

[0031] A mileage difference acquisition module is used to calibrate the mileage of the front differential module and the rear differential module respectively through the front polarity sensor and the rear polarity sensor during the lateral movement, and to acquire the mileage difference between the front differential module and the rear differential module;

[0032] A spacing acquisition module, used to acquire the spacing between the front differential module and the rear differential module;

[0033] A real-time deflection angle acquisition module, used for performing an arcsine operation based on the mileage difference and the distance to acquire the real-time deflection angle of the AGV;

[0034] A regulating speed acquisition module, used for taking the real-time deflection angle as an input of a PI controller and acquiring a regulating speed output by the PI controller;

[0035] The target speed acquisition module is used to combine the adjustment speed with the reference speed of the AGV to obtain a target speed, and control the AGV to perform lateral movement according to the target speed.

[0036] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor are communicatively connected to each other, computer instructions are stored in the memory, and the processor executes an AGV lateral deviation correction method according to the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0037] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute an AGV lateral deviation correction method according to the first aspect or any corresponding embodiment thereof.

[0038] In a fifth aspect, the present invention provides a computer program product, comprising computer instructions, wherein the computer instructions are used to enable a computer to execute an AGV lateral deviation correction method according to the first aspect or any corresponding embodiment thereof.

[0039] The technical solution provided by the present invention may include the following beneficial effects:

[0040] The present invention uses polarity sensors to calibrate the mileage of the front differential module and the rear differential module in real time, effectively reducing the cumulative error caused by long-distance driving, thereby improving the accuracy during the lateral movement. In addition, the mileage difference and spacing between the front differential module and the rear differential module are used to accurately calculate the real-time deflection angle of the AGV through inverse sine calculation, so that the AGV can adjust its posture in real time to ensure the accuracy of the lateral movement path.

[0041] The present invention uses the real-time deflection angle as the input of the PI controller, and outputs a precise adjustment speed through the proportional and integral adjustment of the PI controller. Combined with the reference speed of the AGV, a stable target speed is obtained, thereby achieving dynamic balance and stable control of the AGV during the lateral movement. The problem that the gyroscope cannot correctly identify the AGV due to the excessive length of the AGV and the small lateral angular velocity is avoided, ensuring that the AGV can maintain high precision and high stability even when it is lateral at a low speed. In industrial environments that require high-precision docking, the present invention can significantly improve the lateral docking accuracy of the AGV and reduce problems such as docking failure or equipment damage caused by lateral deviation. In addition, during the lateral movement process, the present invention monitors the operating angle of the differential module in real time through a rotary encoder, and issues an alarm when the angle exceeds the set safety range, prompting manual intervention, effectively preventing safety problems caused by pulling of the differential module or excessive angles. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 is a flow chart of an AGV lateral movement correction method according to an embodiment of the present invention;

[0044] Figure 2 is a flow chart of another AGV lateral deviation correction method according to an embodiment of the present invention;

[0045] Figure 3 Schematic diagram of AGV lateral movement switching and lateral movement correction according to an embodiment of the present invention;

[0046] Figure 4 is a schematic diagram of the principle of a PI controller according to an embodiment of the present invention;

[0047] Figure 5 is a structural block diagram of an AGV lateral movement correction device according to an embodiment of the present invention;

[0048] Figure 6 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0050] According to an embodiment of the present invention, an embodiment of an AGV lateral movement correction method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0051] In this embodiment, a method for correcting lateral movement of an AGV is provided. The method is applied to an AGV, on which a front polarity sensor, a rear polarity sensor, a front differential module, and a rear differential module are installed. Figure 1 is a flow chart of an AGV lateral deviation correction method according to an embodiment of the present invention. Figure 1 As shown, the process includes the following steps:

[0052] Step S101, during the lateral movement, the mileage of the front differential module and the rear differential module are calibrated respectively by the front polarity sensor and the rear polarity sensor, and the mileage difference between the front differential module and the rear differential module is obtained.

[0053] Furthermore, on the lateral movement path of the AGV, this embodiment pastes polar magnetic strips at certain intervals (such as 3 meters). When the polarity sensor reads these magnetic strips, it will record a calibration point, indicating that the differential module has traveled a predetermined distance (such as 3 meters). Since long-distance travel will produce cumulative errors, the calibration points provided by the polarity sensor help correct these errors and ensure the accuracy of the mileage data. This embodiment can obtain the mileage difference between the front differential module and the rear differential module after calibration by comparing the mileage of the two. This difference reflects the lateral deviation between the front and rear of the AGV during the lateral movement.

[0054] Step S102, obtaining a distance between the front differential module and the rear differential module.

[0055] Furthermore, the spacing is fixed, which is the wheelbase between the two sets of differential modules determined when the AGV is designed, and can be used to subsequently calculate the real-time deflection angle of the AGV. The differential module is composed of two drive wheels in a group.

[0056] Step S103, performing an arcsine operation based on the mileage difference and the distance to obtain a real-time deflection angle of the AGV.

[0057] Furthermore, this embodiment uses trigonometric relationships to calculate the real-time deviation angle of the AGV during the lateral movement through the mileage difference and the spacing between the two differential modules. The real-time deviation angle is the deviation angle of the AGV relative to the ideal path during the lateral movement, which can be used to guide subsequent deviation correction control.

[0058] Step S104: using the real-time deflection angle as an input of a PI controller, and obtaining a regulating speed output by the PI controller.

[0059] Furthermore, the PI controller (proportional-integral controller) is a closed-loop control algorithm used to reduce system errors and improve system stability. In this embodiment, the real-time deflection angle is used as the input of the PI controller, and an adjustment speed is output through proportional and integral regulation. The adjustment speed is calculated based on the real-time deflection angle and is used to adjust the driving wheel speed of the AGV to correct the deflection angle so that the AGV can stably move in a predetermined direction.

[0060] Step S105, combining the adjusted speed with the reference speed of the AGV to obtain a target speed, and controlling the AGV to perform lateral movement according to the target speed.

[0061] Furthermore, the reference speed is a basic speed setting for the AGV during the lateral movement, which ensures the normal driving speed of the AGV when there is no deviation. The target speed is the target speed of the AGV during the lateral movement obtained by combining the adjustment speed output by the PI controller with the reference speed. It takes into account both the basic driving speed of the AGV and the need to correct the real-time deviation. This embodiment controls the driving wheels of the AGV to run at a corresponding speed based on the calculated target speed, thereby achieving real-time deviation correction and stable operation of the AGV during the lateral movement.

[0062] In summary, the present invention uses polarity sensors to calibrate the mileage of the front differential module and the rear differential module in real time, effectively reducing the cumulative error caused by long-distance driving, thereby improving the accuracy during the lateral movement. In addition, the mileage difference and spacing between the front differential module and the rear differential module are used to accurately calculate the real-time deflection angle of the AGV through inverse sine calculation, so that the AGV can adjust its posture in real time to ensure the accuracy of the lateral movement path.

[0063] The present invention uses the real-time deflection angle as the input of the PI controller, and outputs a precise adjustment speed through the proportional and integral adjustment of the PI controller. Combined with the reference speed of the AGV, a stable target speed is obtained, thereby achieving dynamic balance and stable control of the AGV during the lateral movement. The problem that the gyroscope cannot correctly identify the AGV due to the excessive length of the AGV and the small lateral angular velocity is avoided, ensuring that the AGV can maintain high precision and high stability even when it is lateral at a low speed. In industrial environments that require high-precision docking, the present invention can significantly improve the lateral docking accuracy of the AGV and reduce problems such as docking failure or equipment damage caused by lateral deviation. In addition, during the lateral movement process, the present invention monitors the operating angle of the differential module in real time through a rotary encoder, and issues an alarm when the angle exceeds the set safety range, prompting manual intervention, effectively preventing safety problems caused by pulling of the differential module or excessive angles.

[0064] In this embodiment, another AGV lateral deviation correction method is provided. The method is applied to an AGV, and the AGV is equipped with a front polarity sensor, a rear polarity sensor, a front differential module, and a rear differential module. Figure 2 FIG. 4 is a flow chart of another AGV lateral deviation correction method according to an embodiment of the present invention. Figure 2 As shown, the process includes the following steps:

[0065] Step S201, receiving a lateral movement instruction and executing a lateral movement action.

[0066] In an optional implementation, the step S201 includes:

[0067] The lateral movement instruction is received, and the initial angle of the front driving wheel and the initial angle of the rear driving wheel of the AGV are respectively obtained through the rotary encoder. The rotary encoder is used to obtain the real-time angle of the differential module.

[0068] The initial angle of the front driving wheel and the initial angle of the rear driving wheel are adjusted to the target angle, and a lateral movement is performed.

[0069] Furthermore, in this embodiment, when the AGV ends the straight-moving mode and switches to the lateral moving mode, it is necessary to ensure that the AGV and the straight-moving magnetic strip are parallel; at this time, the AGV receives the lateral moving instruction and starts to execute the lateral moving action based on the reference speed. Figure 3 The schematic diagram of AGV lateral shift switching and lateral shift correction is shown. Before executing the lateral shift action, the AGV is on the straight magnetic strip and parallel to the straight magnetic strip, and obtains the differential module angles recorded by the motor encoders on the two sets of differential modules (i.e., the front differential module and the rear differential module) (the motor encoder is set inside the motor of the AGV to obtain the real-time speed of the motor and the mileage can be obtained according to the running time) to ensure that the angles of the two sets of differential modules are close to 0 degrees; when the AGV receives the lateral shift instruction, it starts to adjust the lateral shift angle of the drive wheel. The adjusted angle is issued by the controller, and the encoder feedback adjusts the posture in real time, and finally locks the angles of the two sets of differential modules between 89-91 degrees (i.e., near 90 degrees).

[0070] Step S202, during the lateral movement, the mileage of the front differential module and the rear differential module are calibrated respectively by the front polarity sensor and the rear polarity sensor, and the mileage difference between the front differential module and the rear differential module is obtained. That is, in this embodiment, the mileage of the front differential module is calibrated by the front polarity sensor, and the mileage of the rear differential module is calibrated by the rear polarity sensor.

[0071] In an optional embodiment, a corresponding polarity magnetic strip is provided at each target distance (exemplarily, the target distance is 3 meters) on the lateral movement path of the AGV, and the polarity sensor is used to read the polarity magnetic strip on the lateral movement path to calibrate the mileage of each differential module obtained by the motor encoder;

[0072] Each time the polarity sensor reads the polarity magnetic stripe, it represents that the mileage of the corresponding differential module increases by the target distance.

[0073] In an optional implementation, the step of “obtaining the mileage difference between the front differential module and the rear differential module” in step S202 includes:

[0074] Respectively obtaining the front mileage of the front differential module and the rear mileage of the rear differential module;

[0075] A difference calculation is performed based on the front mileage and the rear mileage to obtain a mileage difference between the front differential module and the rear differential module.

[0076] Furthermore, this embodiment obtains the mileage of the two sets of differential modules of the current AGV through the front and rear differential modules, and obtains the mileage difference between the front and rear differential modules based on the two sets of data (the front mileage and the rear mileage).

[0077] The AGV starts the lateral movement process after the angle is locked, and at the same time calculates the mileage of the two groups of differential modules according to the center speed of the differential module. Since long-distance displacement will produce cumulative errors, the mileage needs to be calibrated. In this embodiment, a polarity magnetic strip is pasted on the lateral movement path. The pasting interval can be maintained at 3 meters. Each time the polarity sensor reads the polarity magnetic strip, it means that the mileage of the differential module has reached 3 meters. If it is read for the first time, it means that the mileage of the differential module has reached 3 meters. If it is read for the second time, it means that the mileage of the differential module has reached 6 meters. If the polarity magnetic strip is not read, the mileage is the mileage actually calculated by the driving wheel of the differential module.

[0078] The mileage difference between the two differential modules in this embodiment represents the lateral deviation of the front and rear of the vehicle. The real-time angle of the current AGV when it moves laterally can be calculated based on the lateral deviation and the spacing between the two differential modules. After the lateral movement is started, the front differential module and the rear differential module begin to calculate the mileage. Since each differential module has two driving wheels, there will be a speed difference when moving laterally. In order to reduce the error, this embodiment uses the average of the left and right wheel speeds on each differential module to calculate the mileage.

[0079] The mileage of the differential module can be obtained by the following formula:

[0080] L F =((V 1 +V 2 ) / 2*3.14*R / 60 / i)*0.02;

[0081] Among them, i is the motor reduction ratio, R is the drive wheel diameter, V 1 and V 2 They are the actual speeds of the left and right wheels on a single differential module, in per / min;

[0082] The lateral deviation (i.e., mileage difference) of the front and rear drive wheels can be obtained by the following formula:

[0083] ΔL=L F -L B ;

[0084] Among them, LF is the lateral position of the rear wheel, L B is the lateral position of the front wheels.

[0085] Step S203, obtaining the distance between the front differential module and the rear differential module.

[0086] Step S204: performing an arcsine operation based on the mileage difference and the distance to obtain a real-time deflection angle of the AGV.

[0087] Furthermore, the real-time deflection angle of the AGV body can be obtained by the following formula:

[0088] θ = arcsin(ΔL / d);

[0089] Among them, d is the distance (wheelbase) between the two sets of differential modules, and ΔL is the mileage difference. The lateral deviation correction process of the AGV through polarity sensors and mileage calibration can be simplified into a triangular model. When the model is built, the mileage difference between the front and rear differential modules and the distance (wheelbase) between the two differential modules can be used to calculate the current AGV lateral deviation angle.

[0090] Step S205, converting the real-time deflection angle into radians, and inputting the deflection angle into the PI controller for proportional and integral adjustment, so as to obtain the adjustment speed output by the PI controller.

[0091] For further information, see Figure 4 The schematic diagram of the PI controller shown in the figure shows that after obtaining the real-time deflection angle of the AGV when it moves sideways, the PI controller is applied to the real-time deflection angle, that is, the arc value of the AGV's sideways deflection angle is used as the input of the PI controller for self-control adjustment. After adding proportional and integral adjustment, the speed is fed back by the motor encoder, and the controller program calculation can obtain the error result in real time, thus forming a closed-loop control, and integrating the controller output result with the reference speed of the AGV. The calculation formula of the PI controller is as follows:

[0092]

[0093] Among them, U t is the output of the PI controller at time t, K p is the proportional gain, which determines the direct impact of the error signal on the controller output, e(t) is the error signal, which is the difference between the expected value and the actual value, K i is the integral gain, which determines the impact of the error accumulated over time on the controller output.

[0094] In order to facilitate calculation in the program and according to the software requirements, angle calculations need to be converted into radians. Therefore, in this embodiment, the calculated deflection angle of the AGV during lateral movement needs to be converted into radians. The formula is:

[0095] θ rad =θ*3.14 / 180.

[0096] When calculating and sending the speed to the drive unit, it is necessary to pay attention to the effective units recognized by the drive unit. Since the AGV speed is mostly expressed in m / s or m / min, but the AGV drive unit cannot recognize the value of this unit, it is necessary to convert it into a unit that the drive unit can recognize (here is an example of converting m / min to per / min). The specific formula is:

[0097] V per =(V*i) / (3.14*R);

[0098] Among them, i is the motor reduction ratio; R is the driving wheel diameter.

[0099] One thing that needs to be noted is that the integral term of the PI controller needs to be cleared when the lateral movement starts or ends. Since the function of the integral term is to reduce the accumulated error over a long period of time and eliminate the static error, if it is not cleared, the error will easily affect the output of the PI controller at the beginning of the next lateral movement, thereby causing accuracy error.

[0100] Step S206, combining the adjusted speed with the reference speed of the AGV to obtain a target speed, and controlling the AGV to perform lateral movement according to the target speed.

[0101] In an optional implementation, step S206 includes:

[0102] Add or subtract the adjustment speed from the reference speed of the AGV to obtain the target speed of each differential module;

[0103] The target speed is converted into units and sent to the control unit of the corresponding differential module. The control unit is the driver of the differential module, and the unit conversion is to enable the control unit (driver) to effectively identify it.

[0104] Furthermore, after completing the preconditions for starting the lateral movement, this embodiment clears the integral term of the PI controller, the AGV starts to lateralize, and the controller sends the lateral movement speed of each wheel. During the initial lateral movement, the lateral movement is based on the AGV reference speed. After obtaining the adjustment speed output by the PI controller, the lateral movement is based on the target speed after the integration of the AGV reference speed and the adjustment speed. During the lateral movement, the speed of the driving wheel on the differential module is calculated inside the controller based on the feedback speed of the motor encoder according to some mechanical parameters, so that the current running speed of the AGV can be monitored in real time and adjusted.

[0105] Furthermore, the reference speed is a preset speed value of the AGV under standard operating conditions, which serves as the basis for adjusting and controlling the speed and represents the normal operating speed of the AGV. In this embodiment, the adjustment speed is added or subtracted from the reference speed to obtain the target speed of each differential module. If the AGV needs to accelerate to reach the target position faster, the adjustment speed is added to the reference speed; if it needs to decelerate or change direction, the adjustment speed is subtracted from the reference speed.

[0106] Furthermore, this embodiment adds a speed reference to the output result of the PI controller to finally issue the target speed of the differential module, so as to achieve the effect of deceleration of the leading wheel and acceleration of the lagging wheel. In order to ensure that there is no derailment and other problems during the lateral movement, this embodiment sets the front differential module as the main one. The differential module always moves laterally along the direction of the magnetic stripe, and adopts a pre-aiming and correction algorithm to control and calculate the heading angle of the magnetic stripe data. Therefore, the driving wheel speed on the front differential module is equal to the output result after the pre-aiming and correction algorithm and the mileage correction algorithm. In order to prevent the pulling of the front and rear differential modules, the driving wheel speed on the rear differential module is equal to the output result of the product of the mileage correction algorithm output and the proportional coefficient and the difference between the front and rear rotary encoders. The connecting rod model follows that the speed components of the front and rear differential modules along the vehicle body direction are equal. In actual program writing, it is necessary to avoid the situation where the denominator or numerator is 0 and the data suddenly changes, so as to prevent the problem of large floating swing of AGV or program error.

[0107] Step S207: During the lateral movement, the operating angle of the AGV is monitored in real time by the rotary encoder, and when the operating angle of the AGV exceeds a set range, an alarm message is output.

[0108] Furthermore, during the period from the start to the end of the lateral movement, there will be some problems with the differential module angle being too large, so the front differential module and the rear differential module will be corrected. Therefore, it is necessary to protect the cables of the differential module from being pulled, and there must be no pulling between the drive wheels. The front differential module and the rear differential module must always be kept within a safe angle range for correction during the lateral movement. A safety protection is performed through the real-time angle feedback of the rotary encoder on the differential module. When the operating angle exceeds the set safety angle, the AGV alarms, which is mapped to the touch screen to prompt the alarm content, indicating that human intervention is required.

[0109] Step S208, when the lateral movement of the AGV ends, the integral term of the PI controller is reset to zero.

[0110] In summary, the present invention uses polarity sensors to calibrate the mileage of the front differential module and the rear differential module in real time, effectively reducing the cumulative error caused by long-distance driving, thereby improving the accuracy during the lateral movement. In addition, the mileage difference and spacing between the front differential module and the rear differential module are used to accurately calculate the real-time deflection angle of the AGV through inverse sine calculation, so that the AGV can adjust its posture in real time to ensure the accuracy of the lateral movement path.

[0111] The present invention uses the real-time deflection angle as the input of the PI controller, and outputs a precise adjustment speed through the proportional and integral adjustment of the PI controller. Combined with the reference speed of the AGV, a stable target speed is obtained, thereby achieving dynamic balance and stable control of the AGV during the lateral movement. The problem that the gyroscope cannot correctly identify the AGV due to the excessive length of the AGV and the small lateral angular velocity is avoided, ensuring that the AGV can maintain high precision and high stability even when it is lateral at a low speed. In industrial environments that require high-precision docking, the present invention can significantly improve the lateral docking accuracy of the AGV and reduce problems such as docking failure or equipment damage caused by lateral deviation. In addition, during the lateral movement process, the present invention monitors the operating angle of the differential module in real time through a rotary encoder, and issues an alarm when the angle exceeds the set safety range, prompting manual intervention, effectively preventing safety problems caused by pulling of the differential module or excessive angles.

[0112] In this embodiment, an AGV lateral deviation correction device is also provided, which is used to implement the above-mentioned embodiments and preferred embodiments, and will not be repeated here. As used below, the term "module" can implement a combination of software and / or hardware for a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0113] This embodiment provides an AGV lateral deviation correction device, which is applied to the AGV. The AGV is equipped with a front polarity sensor, a rear polarity sensor, a front differential module and a rear differential module. Figure 5 As shown, including:

[0114] The mileage difference acquisition module 501 is used to calibrate the mileage of the front differential module and the rear differential module respectively through the front polarity sensor and the rear polarity sensor during the lateral movement, and acquire the mileage difference between the front differential module and the rear differential module;

[0115] A spacing acquisition module 502 is used to acquire the spacing between the front differential module and the rear differential module;

[0116] A real-time deflection angle acquisition module 503 is used to perform an arcsine operation based on the mileage difference and the distance to obtain the real-time deflection angle of the AGV;

[0117] The regulating speed acquisition module 504 is used to use the real-time deflection angle as the input of the PI controller and obtain the regulating speed output by the PI controller;

[0118] The target speed acquisition module 505 is used to combine the adjustment speed with the reference speed of the AGV to obtain a target speed, and control the AGV to perform lateral movement according to the target speed.

[0119] In some optional embodiments, the device is also used for:

[0120] Receive a lateral movement instruction, and obtain the initial angle of the front drive wheel and the initial angle of the rear drive wheel of the AGV through the rotary encoder;

[0121] The initial angle of the front driving wheel and the initial angle of the rear driving wheel are adjusted to the target angle, and a lateral movement is performed.

[0122] In some optional embodiments, a corresponding polarity magnetic strip is provided at each target distance interval on the traverse path of the AGV, and the polarity sensor is used to read the polarity magnetic strip on the traverse path to calibrate the mileage of each differential module obtained by the motor encoder;

[0123] Each time the polarity sensor reads the polarity magnetic stripe, it represents that the mileage of the corresponding differential module increases by the target distance.

[0124] In some optional implementations, the mileage difference acquisition module 501 is further used to:

[0125] Respectively obtaining the front mileage of the front differential module and the rear mileage of the rear differential module;

[0126] A difference calculation is performed based on the front mileage and the rear mileage to obtain a mileage difference between the front differential module and the rear differential module.

[0127] In some optional implementations, the adjustment speed acquisition module 504 is further used to:

[0128] The real-time deflection angle is converted into radians and input into the PI controller for proportional and integral adjustment to obtain the adjustment speed output by the PI controller.

[0129] In some optional implementations, the target speed acquisition module 505 is further used to:

[0130] Add or subtract the adjustment speed from the reference speed of the AGV to obtain the target speed of each differential module;

[0131] The target speed conversion is converted into units and sent to the control unit of the corresponding differential module.

[0132] In some optional embodiments, the device is also used for:

[0133] During the lateral movement, the rotary encoder monitors the running angle of the AGV in real time, and outputs an alarm message when the running angle of the AGV exceeds a set range.

[0134] In some optional embodiments, the device is also used for:

[0135] At the end of the AGV's traverse operation, the integral term of the PI controller is reset to zero.

[0136] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0137] See also Figure 6 , Figure 6 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Figure 6 As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 6 A processor 10 is taken as an example.

[0138] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0139] The memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0140] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0141] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0142] The computer device further comprises a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0143] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0144] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0145] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the defined scope.

Claims

1. An AGV lateral deviation correction method, characterized in that: The method is applied to the AGV, on which a front polarity sensor, a rear polarity sensor, a front differential module and a rear differential module are installed, and the method includes: During the lateral movement, the mileage of the front differential module and the rear differential module are calibrated respectively by the front polarity sensor and the rear polarity sensor, and the mileage difference between the front differential module and the rear differential module is obtained; Obtaining a distance between the front differential module and the rear differential module; Performing an arcsine operation based on the mileage difference and the distance to obtain a real-time deflection angle of the AGV; Using the real-time deflection angle as an input of a PI controller, and obtaining a regulation speed output by the PI controller; The adjustment speed is combined with the reference speed of the AGV to obtain a target speed, and the AGV is controlled to perform lateral movement according to the target speed.

2. The method according to claim 1, characterized in that The differential module is also provided with a rotary encoder. Before performing the lateral movement, the method further includes: Receiving a lateral movement instruction, and respectively obtaining an initial angle of a front driving wheel and an initial angle of a rear driving wheel of the AGV through the rotary encoder; The initial angles of the front driving wheels and the rear driving wheels are adjusted to target angles, and a lateral movement is performed.

3. The method according to claim 2, characterized in that A corresponding polarity magnetic strip is provided at each target distance interval on the lateral movement path of the AGV, and the polarity sensor is used to read the polarity magnetic strip on the lateral movement path to calibrate the mileage of each differential module obtained by the motor encoder; Each time the polarity sensor reads the polarity magnetic stripe, it represents that the mileage of the corresponding differential module increases by the target distance.

4. The method according to claim 1, characterized in that: The obtaining of the mileage difference between the front differential module and the rear differential module includes: Respectively obtaining the front mileage of the front differential module and the rear mileage of the rear differential module; A difference calculation is performed based on the front mileage and the rear mileage to obtain a mileage difference between the front differential module and the rear differential module.

5. The method according to claim 1, characterized in that The method of using the real-time deflection angle as an input of a PI controller and obtaining a regulating speed output by the PI controller comprises: The real-time deflection angle is converted into radians and input into the PI controller for proportional and integral regulation to obtain the regulation speed output by the PI controller.

6. The method according to claim 1, characterized in that The step of combining the adjustment speed with the reference speed of the AGV to obtain a target speed includes: Adding or subtracting the adjustment speed from the reference speed of the AGV to obtain a target speed of each differential module; The target speed conversion is unit-converted and sent to a control unit of a corresponding differential module.

7. The method according to claim 2, characterized in that: The method further comprises: During the lateral movement, the operating angle of the AGV is monitored in real time by the rotary encoder, and when the operating angle of the AGV exceeds a set range, an alarm message is output.

8. The method according to any one of claims 1 to 7, characterized in that: The method further comprises: At the end of the traverse operation of the AGV, the integral term of the PI controller is reset to zero.

9. An AGV lateral deviation correction device, characterized in that: The device is applied to the AGV, and the AGV is equipped with a front polarity sensor, a rear polarity sensor, a front differential module, and a rear differential module. The device includes: A mileage difference acquisition module is used to calibrate the mileage of the front differential module and the rear differential module respectively through the front polarity sensor and the rear polarity sensor during the lateral movement, and to acquire the mileage difference between the front differential module and the rear differential module; A spacing acquisition module, used to acquire the spacing between the front differential module and the rear differential module; A real-time deflection angle acquisition module, used for performing an arcsine operation based on the mileage difference and the distance to acquire the real-time deflection angle of the AGV; A regulating speed acquisition module, used for taking the real-time deflection angle as an input of a PI controller and acquiring a regulating speed output by the PI controller; The target speed acquisition module is used to combine the adjustment speed with the reference speed of the AGV to obtain a target speed, and control the AGV to perform lateral movement according to the target speed.

10. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the AGV lateral deviation correction method according to any one of claims 1 to 8 by executing the computer instructions.

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