Track control method and device of automatic guided vehicle and automatic guided vehicle

Abstract

The invention discloses a track control method and device of an automatic guided vehicle and the automatic guided vehicle, and the track control method comprises the following steps: in the driving process of the automatic guided vehicle, acquiring odometer data of the automatic guided vehicle; and according to the odometer data, determining a driving track of the automatic guided vehicle, and storing the driving track. The historical running track information of the automatic guided vehicle can be conveniently recorded in real time, and the automatic guided vehicle can be helped to carry out applications such as but not limited to deviation correction.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and more specifically to a trajectory control method and device for an automatic guided vehicle, and an automatic guided vehicle. Background Art

[0002] With the development of automatic navigation technology, AGV can be applied to scenarios such as but not limited to automatic hauling, logistics warehousing, etc., to supplement or replace manual labor and improve transportation efficiency. In the relevant technology, during the navigation control process of the AGV, the main focus is on whether the AGV is traveling at a preset speed and a preset planned route. Summary of the invention

[0003] The present application is proposed to solve at least one of the above problems. According to a first aspect of the present application, a trajectory control method for an automated guided vehicle is provided, the trajectory control method comprising: obtaining odometer data of the automated guided vehicle during the driving process of the automated guided vehicle; determining the driving trajectory of the automated guided vehicle according to the odometer data, and saving the driving trajectory.

[0004] In one embodiment of the present application, the odometer data of the automatic guided vehicle is obtained during the driving of the automatic guided vehicle, including: obtaining the rotational speed of the left wheel and the rotational speed of the right wheel during the driving of the automatic guided vehicle; determining the linear speed and angular speed of the automatic guided vehicle according to the rotational speed, and the wheel spacing and wheel radius of the left wheel and the right wheel, and using the linear speed and angular speed of the automatic guided vehicle as the odometer data.

[0005] In one embodiment of the present application, determining the driving trajectory of the automatic guided vehicle according to the odometer data includes: drawing the driving trajectory of the automatic guided vehicle according to the linear velocity and angular velocity of the automatic guided vehicle.

[0006] In one embodiment of the present application, the trajectory control method further includes: when the automatic guided vehicle deviates from the ideal driving trajectory, controlling the automatic guided vehicle to retreat to a position that does not deviate from the ideal driving trajectory according to the saved driving trajectory.

[0007] In one embodiment of the present application, controlling the automatic guided vehicle to retract to a position that does not deviate from the ideal driving trajectory based on the saved driving trajectory includes: determining the steering angle of the automatic guided vehicle during the retraction process based on the saved driving trajectory; and controlling the automatic guided vehicle to track the saved driving trajectory and retract based on the steering angle.

[0008] In one embodiment of the present application, the trajectory control method further includes: during the driving process of the automatic guided vehicle, if it is detected that the deviation distance of the automatic guided vehicle relative to the ideal driving trajectory is greater than a preset threshold, determining that the automatic guided vehicle deviates from the ideal driving trajectory.

[0009] In one embodiment of the present application, the ideal driving trajectory includes a magnetic stripe trajectory represented by a magnetic stripe, and a magnetic sensor is provided on the automatic guided vehicle; during the driving of the automatic guided vehicle, if it is detected that the deviation distance of the automatic guided vehicle relative to the ideal driving trajectory is greater than a preset threshold, then the automatic guided vehicle is determined to have deviated from the ideal driving trajectory, including: during the driving of the automatic guided vehicle, controlling the magnetic sensor to sense the magnetic force intensity; if the magnetic force intensity sensed by the magnetic sensor is less than a preset intensity threshold, then it is determined that the automatic guided vehicle has deviated from the ideal driving trajectory.

[0010] In one embodiment of the present application, controlling the automatic guided vehicle to retract to a position that does not deviate from the ideal driving trajectory according to the saved driving trajectory includes: controlling the automatic guided vehicle to retract according to the saved driving trajectory while also controlling the magnetic intensity sensed by the magnetic sensor; when the magnetic intensity sensed by the magnetic sensor is not less than the preset intensity threshold, controlling the automatic guided vehicle to stop retracting, and determining that the automatic guided vehicle retracts to a position that does not deviate from the ideal driving trajectory.

[0011] In one embodiment of the present application, the automatic guided vehicle is controlled to retract to a position that does not deviate from the ideal driving trajectory based on the saved driving trajectory, and also includes: if the magnetic strength sensed by the magnetic sensor is still less than the preset strength threshold after the retraction time of the automatic guided vehicle reaches a preset adjustment time, the automatic guided vehicle is controlled to stop retracting and an alarm signal is issued.

[0012] In one embodiment of the present application, the ideal driving trajectory includes a ribbon trajectory represented by a ribbon, and a visual sensor is provided on the automatic guided vehicle, and the visual sensor is configured to capture an image of the automatic guided vehicle in a preset direction; during the driving of the automatic guided vehicle, if it is detected that the deviation distance of the automatic guided vehicle relative to the ideal driving trajectory is greater than a preset threshold, then it is determined that the automatic guided vehicle deviates from the ideal driving trajectory, including: during the driving of the automatic guided vehicle, controlling the visual sensor to capture an image of the automatic guided vehicle in a preset direction; if the position of the ribbon trajectory in the image is outside a preset image area, then it is determined that the automatic guided vehicle deviates from the ideal driving trajectory.

[0013] In one embodiment of the present application, controlling the automatic guided vehicle to retract to a position that does not deviate from the ideal driving trajectory based on the saved driving trajectory includes: controlling the automatic guided vehicle to retract based on the saved driving trajectory, and also controlling the visual sensor to capture an image of the automatic guided vehicle in a preset direction; when the position of the ribbon track in the image is within the preset image area, controlling the automatic guided vehicle to stop retracting, and determining that the automatic guided vehicle retracts to a position that does not deviate from the ideal driving trajectory.

[0014] In one embodiment of the present application, the automatic guided vehicle is controlled to retract to a position that does not deviate from the ideal driving trajectory based on the saved driving trajectory, and also includes: if the position of the ribbon trajectory in the image is still outside the preset image area after the retraction time of the automatic guided vehicle reaches a preset adjustment time, the automatic guided vehicle is controlled to stop driving and an alarm signal is issued.

[0015] According to the second aspect of the present application, there is also provided a trajectory control device for an automatic guided vehicle, the trajectory control device comprising: a storage medium and a processor, the storage medium storing a computer program run by the processor, the computer program, when run by the processor, causing the processor to execute any one of the above-mentioned trajectory control methods for an automatic guided vehicle.

[0016] According to a third aspect of the present application, an automatic guided vehicle is further provided, and the automatic guided vehicle comprises: a trajectory control device of any one of the automatic guided vehicles described above.

[0017] According to the trajectory control method and device of the automated guided vehicle, and the automated guided vehicle provided in the embodiments of the present application, during the driving process of the automated guided vehicle, the odometer data of the automated guided vehicle is acquired in real time, and based on the odometer data, the driving trajectory of the automated guided vehicle is determined, and the obtained driving trajectory is saved, so as to facilitate real-time recording of the historical operation trajectory information of the automated guided vehicle, and help the automated guided vehicle to perform applications such as but not limited to deviation correction. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0019] Figure 1 A flow chart of a trajectory control method for an automatic guided vehicle according to an embodiment of the present invention;

[0020] Figure 2A schematic diagram showing the linear velocity and angular velocity of an automatic guided vehicle and the wheel speed of a wheel according to an embodiment of the present invention;

[0021] Figure 3 A schematic diagram of an ideal driving trajectory of an automatic guided vehicle and a driving trajectory determined according to odometer data according to an embodiment of the present invention;

[0022] Figure 4 A schematic diagram showing an automatic guided vehicle deviating from an ideal driving trajectory according to an embodiment of the present invention;

[0023] Figure 5 A schematic diagram of an automatic guided vehicle returning to an ideal driving trajectory according to an embodiment of the present invention;

[0024] Figure 6 A schematic diagram of the magnetic force intensity induced by a magnetic sensor according to an embodiment of the present invention;

[0025] Figure 7 A flow chart of a trajectory control method for an automatic guided vehicle according to another embodiment of the present invention;

[0026] Figure 8 The present invention is a schematic block diagram of a trajectory control device for an automatic guided vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the present invention more obvious, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described in the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the present invention.

[0028] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0029] It should be understood that the present invention can be implemented in different forms and should not be interpreted as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0030] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, confirm the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0031] In order to fully understand the present invention, a detailed structure will be presented in the following description to illustrate the technical solution proposed by the present invention. The optional embodiments of the present invention are described in detail as follows, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0032] In the related art, the method of recording the driving trajectory of the automatic guided vehicle is mainly to set various types of distance sensors on the automatic guided vehicle, detect the distance between the automatic guided vehicle and the reference object in real time, and then draw the driving trajectory of the automatic guided vehicle according to the distance information. However, this trajectory drawing method not only requires the use of a large number of distance sensors and reference objects, but also requires a large amount of computing resources to perform complex calculations when drawing the driving trajectory of the automatic guided vehicle according to the distance information, resulting in high costs. In order to solve the above technical problems, the present application provides the following implementation methods.

[0033] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0034] First, an application scenario of the trajectory control method of an automated guided vehicle illustrated in the example of the present application is introduced. The trajectory control method of an automated guided vehicle is applied to the trajectory management and control process of an automated guided vehicle during driving.

[0035] refer to Figure 1 , an embodiment of the present application provides a trajectory control method for an automatic guided vehicle, the trajectory control method comprising:

[0036] Step 1: Acquire odometer data of the automatic guided vehicle during its driving process;

[0037] Step 2: Determine the driving trajectory of the automatic guided vehicle based on the odometer data and save the driving trajectory.

[0038] In the above scheme, during the driving process of the automatic guided vehicle, the odometer data of the automatic guided vehicle is obtained in real time, and the driving trajectory of the automatic guided vehicle is determined based on the odometer data, and the obtained driving trajectory is saved, so as to facilitate real-time recording of the historical running trajectory information of the automatic guided vehicle, which is helpful for the automatic guided vehicle to perform applications such as but not limited to deviation correction. The above steps are described in detail below with reference to the accompanying drawings.

[0039] First, refer to Figure 1 During the driving process of the automatic guided vehicle, the odometer data of the automatic guided vehicle can be obtained in real time. The odometer data may include information such as but not limited to the speed and posture of the automatic guided vehicle. The speed information may include information such as but not limited to the linear velocity, angular velocity, linear acceleration, angular acceleration, etc. of the automatic guided vehicle. The posture information may include information such as but not limited to the displacement and turning angle of the automatic guided vehicle. There are many ways to obtain the odometer data of the automatic guided vehicle. Several methods are introduced as examples below.

[0040] Exemplarily, when obtaining the odometer data of the automatic guided vehicle during the driving process of the automatic guided vehicle, the following method can be adopted: during the driving process of the automatic guided vehicle, the rotation speed of the left wheel and the rotation speed of the right wheel are obtained; the wheel spacing and wheel radius of the left wheel and the right wheel can also be obtained in advance; then, according to the rotation speed, and the wheel spacing and wheel radius of the left wheel and the right wheel, the linear speed and angular velocity of the automatic guided vehicle are determined, and the linear speed and angular velocity of the automatic guided vehicle are used as the odometer data.

[0041] First of all, it needs to be explained that the left wheel and the right wheel of the automatic guided vehicle refer to: based on the direction of the front of the automatic guided vehicle, the left wheel of the automatic guided vehicle is located on the left side of the automatic guided vehicle, and the right wheel of the automatic guided vehicle is located on the right side of the automatic guided vehicle. The left wheel and the right wheel here can be two coaxial wheels. Among them, the wheel spacing between the left wheel and the right wheel refers to: the distance between the left wheel and the right wheel, specifically, the spacing between the coaxial left wheel and the right wheel. The wheel radius refers to: the wheel radius of the left wheel and the wheel radius of the right wheel. When applied, the wheels of the automatic guided vehicle all use wheels with the same wheel radius, so you only need to obtain the wheel radius of one of the wheels of the automatic guided vehicle.

[0042] The units of the rotation speed of the left wheel and the right wheel can be radians per second, circles per second, etc., which represent the rotation speed of the wheels. Specifically, during the driving process of the automatic guided vehicle, the rotation speed of the left wheel and the right wheel can be obtained in a variety of ways. For example, a rotation speed sensor can be set on the left wheel and the right wheel, and the rotation speed of the left wheel and the right wheel can be obtained in real time through the rotation speed sensor.

[0043] After obtaining the rotational speeds of the left and right wheels, as well as the wheel spacing and wheel radius of the left and right wheels, the linear velocity and angular velocity of the automatic guided vehicle can be calculated based on the information obtained. The specific calculation method can be adopted in a variety of ways.

[0044] Exemplarily, an odometer estimation method can be used. It should be explained that the odometer is an estimation method that estimates the position of the automatic guided vehicle (AGV) by the rotation speed of the wheels of the automatic guided vehicle after the kinematic model of the automatic guided vehicle (AGV) is modeled. The working mode of the odometer can basically be regarded as the inverse of the differential drive. The differential drive is to solve the rotation speed of the left wheel and the right wheel of the automatic guided vehicle given the linear velocity and angular velocity of the movement of the automatic guided vehicle, and the odometer estimates the linear velocity and angular velocity of the automatic guided vehicle based on the rotation speed of the left wheel and the rotation speed of the right wheel. In addition, the odometer also needs to integrate the linear velocity and angular velocity of the automatic guided vehicle, so that a rough positioning can be obtained. Due to measurement errors and the existence of unmodeled factors such as wheel slip, it is very inaccurate to use the odometer to estimate the posture, and this error will continue to accumulate with the effect of integration.

[0045] The following are some examples of calculation methods. Figure 2 As shown, the symbols and schematic diagram of differential drive are used. The automatic guided vehicle moves in the O coordinate system, and the local coordinate system A coordinate system is established with the midpoint of the two wheels as the origin, which moves with the automatic guided vehicle. Point C is the instantaneous center of rotation of particle A. L and r are the wheel spacing and wheel radius of the automatic guided vehicle respectively. Assume that the rotation speed of the left wheel and the rotation speed of the right wheel are nL and nR respectively, in radians per second. According to the geometric relationship, the relationship between the rotation speed of the wheel and the linear velocity v and angular velocity ω of the automatic guided vehicle can be written:

[0046] n R =(v+0.5ωl) / r

[0047] nL=(v-0.5ωl) / r

[0048] By inverting the above formula, we can estimate the linear velocity v and angular velocity ω of the automatic guided vehicle based on the rotation speed of the left wheel and the rotation speed of the right wheel:

[0049]

[0050]

[0051] After the linear velocity and angular velocity of the automatic guided vehicle are calculated, the linear velocity and angular velocity of the automatic guided vehicle may be used as odometer data of the automatic guided vehicle.

[0052] Next, refer to Figure 1According to the odometer data, the driving track of the automatic guided vehicle is determined and saved. Specifically, the driving track of the automatic guided vehicle can be determined according to the odometer data in a variety of ways, which are specifically related to the type of odometer data. An exemplary method is introduced as follows.

[0053] For example, when determining the driving trajectory of the automatic guided vehicle based on the odometer data, the linear velocity and angular velocity in the odometer data can be obtained, that is, the linear velocity and angular velocity of the automatic guided vehicle are used as the basis for determining the driving trajectory of the automatic guided vehicle. Specifically, the driving trajectory of the automatic guided vehicle is drawn according to the linear velocity and angular velocity of the automatic guided vehicle. There are many ways to draw the trajectory. The following are some examples. For example, refer to Figure 3 , the historical position of the AGV estimated by the odometer can be plotted in the O coordinate system, and a similar result can be obtained. Figure 3 The curve. Figure 3 It can be seen that the relationship diagram between the ideal driving trajectory of the automatic guided vehicle and the driving trajectory determined according to the odometer data.

[0054] Exemplary, reference Figure 4 and Figure 5 , the trajectory control method may also include: when the automatic guided vehicle deviates from the ideal driving trajectory, according to the saved driving trajectory, controlling the automatic guided vehicle to retreat to a position that does not deviate from the ideal driving trajectory. It should be explained that the position that does not deviate from the ideal driving trajectory refers to: the position where the automatic guided vehicle can identify the ideal driving trajectory and track the ideal driving trajectory for navigation. Specifically, the automatic guided vehicle may be located on the ideal driving trajectory, or the distance from the ideal driving trajectory may be less than a preset deviation distance, so that the automatic guided vehicle is identified as not deviating from the ideal driving trajectory. Exemplarily, controlling the automatic guided vehicle to retreat to a position that does not deviate from the ideal driving trajectory may include: controlling the automatic guided vehicle to retreat to a position before deviating from the ideal driving trajectory. Exemplarily, controlling the automatic guided vehicle to retreat to a position that does not deviate from the ideal driving trajectory may also include: controlling the automatic guided vehicle to retreat to a position that is not before deviating from the ideal driving trajectory, and retreating to other positions that do not deviate from the ideal driving trajectory.

[0055] In the related art, after the magnetic navigation / ribbon navigation automatic guided vehicle derails, manual processing is required. The specific manual processing method is to control the automatic guided vehicle to return to the route through the panel or handle of the automatic guided vehicle, and the automatic guided vehicle cannot recover automatically. Specifically, during the operation of the automatic guided vehicle, the reason for a large deviation from the ideal driving trajectory (i.e. derailment) may be: Figure 4As shown, during the turning process of the automatic guided vehicle, due to the large inertia of the automatic guided vehicle traveling in a straight line, the automatic guided vehicle may not adjust the direction in time, resulting in the magnetic sensor failing to detect the magnetic strength signal of the tape track, causing the automatic guided vehicle to stop.

[0056] In addition, it is necessary to introduce that the ideal driving trajectory is the driving trajectory planned in advance for the automatic guided vehicle. During the driving process, the automatic guided vehicle needs to follow the ideal driving trajectory and cannot deviate too much from the ideal driving trajectory. There are many ways to determine the ideal driving trajectory. Exemplarily, the ideal driving trajectory can be a magnetic stripe track formed by a magnetic strip. Exemplarily, a magnetic strip representing the ideal driving trajectory can be pre-attached on the driving surface, and the trajectory of the magnetic strip extending forms a magnetic stripe track, and the magnetic stripe track is used as the ideal driving trajectory. Exemplarily, a color ribbon representing the ideal driving trajectory can also be pre-attached on the driving surface, and the trajectory of the color ribbon extending forms a color ribbon track, and the color ribbon track is used as the ideal driving trajectory.

[0057] Compared with the related art, the present application, in this embodiment, also adds a deviation correction function for the automatic guided vehicle when the deviation from the ideal driving trajectory is too large. After the automatic guided vehicle is found to have deviated from the ideal driving trajectory, the previously saved driving trajectory can be called up, and according to the saved driving trajectory, the "original route" retreat "reverse" method is adopted to control the automatic guided vehicle to retreat to a position that has not deviated from the ideal driving trajectory. After the automatic guided vehicle derails relative to the ideal driving trajectory, the function of automatically retreating to the ideal driving trajectory can be realized, that is, by retreating the automatic guided vehicle, the automatic guided vehicle returns to the position before it deviates from the ideal driving trajectory. Thereby, manual intervention can be reduced, the manual workload during the operation of the automatic guided vehicle can be reduced, and safety problems can be avoided.

[0058] Specifically, refer to Figure 5 and Figure 7 , the solution shown in the embodiment of the present application is: 1. During the driving process of the automatic guided vehicle, the odometer data records the driving trajectory of the automatic guided vehicle in a period of historical time; 2. After the automatic guided vehicle derails, the recorded historical driving trajectory is called out, and "reverse rollback" is performed according to the historical driving trajectory; 3. Within the preset adjustment time, when the automatic guided vehicle returns to the ideal driving trajectory, the "reverse rollback" is stopped; 4. Restart forward driving and resume normal operation. Figure 5As shown, the driving route of the automatic guided vehicle in the derailment stage is: A->B. The driving route of the automatic guided vehicle in the retraction stage is: B->A. The driving route of the automatic guided vehicle in the re-driving stage is: A->C. In this embodiment of the present application, in the scenario where the automatic guided vehicle probabilistically turns and derails, a method for retracing the track by memorizing the previous driving route can be used to enable the automatic guided vehicle to return to the magnetic strip track for driving, thereby reducing the need for manual processing.

[0059] Exemplarily, in the process of controlling the automatic guided vehicle to retract, the automatic guided vehicle retracts in a tracking and retracting process according to a known trajectory, wherein the known trajectory is a saved driving trajectory, so that the automatic guided vehicle is controlled to retract by tracking the saved driving trajectory.

[0060] Exemplary, reference Figure 3 , Figure 5 and Figure 7 , according to the saved driving trajectory, controlling the automatic guided vehicle to retreat to a position that does not deviate from the ideal driving trajectory, can include: determining the steering angle of the automatic guided vehicle during the retreat process according to the saved driving trajectory; according to the steering angle, controlling the automatic guided vehicle to track the saved driving trajectory for retreat. That is, in the retreat process, the steering angle of the automatic guided vehicle during the retreat process is mainly concerned, and the retreat angular velocity and retreat linear velocity of the automatic guided vehicle can be the same as or different from those in the previous driving process, so that the retreat process of the automatic guided vehicle and the previous driving process following the ideal driving trajectory belong to two completely independent control processes. The above-mentioned method of determining the steering angle of the automatic guided vehicle during the retreat process according to the saved driving trajectory can be adopted in a variety of ways. Exemplarily, a pure visual tracking method (PurePursuit algorithm) or a Stanley algorithm can be used to determine the steering angle of the automatic guided vehicle during the retreat process according to the saved driving trajectory, so that the automatic guided vehicle can retreat along the previously saved driving trajectory.

[0061] It should be noted that the AGV may not make a U-turn during the retreat process, but may switch the front of the AGV during the ideal driving trajectory to the rear of the AGV, and switch the rear of the AGV during the ideal driving trajectory to the front of the AGV, so as to control the AGV to reverse and retreat. Of course, in other embodiments, the AGV may be controlled to make a U-turn on the spot first, and then the AGV may be controlled to retreat along the previously saved driving trajectory.

[0062] Exemplary, reference Figure 3 , Figure 5 and Figure 7In the process of using the pure vision tracking method (Pure Pursuit algorithm) to determine the steering angle of the automatic guided vehicle during the retreat process according to the saved driving trajectory, if the automatic guided vehicle does not turn around on the spot but directly reverses and retreats, the rear wheels of the automatic guided vehicle can be used as the front wheels during the retreat process. If the automatic guided vehicle turns around on the spot, the front wheels of the automatic guided vehicle can still be used as the front wheels in the process of calculating the steering angle. After that, the steering angle of the automatic guided vehicle during the retreat process is calculated using the pure vision tracking method. During the calculation process, it is necessary to select a section from the saved driving trajectory as the trajectory containing the target point in the pure vision tracking method so that the automatic guided vehicle can track it. In this way, a longer section can be selected from the saved driving trajectory as the trajectory containing the target point in the pure vision tracking method, so that the tracking motion has a higher smoothness. Of course, a shorter section can also be selected from the saved driving trajectory as the trajectory containing the target point in the pure vision tracking method, so that the tracking motion has a higher accuracy.

[0063] Exemplary, reference Figure 3 , Figure 5 and Figure 7 In the process of using the Stanley algorithm to determine the steering angle of the automatic guided vehicle during the retreat process according to the saved driving trajectory, if the automatic guided vehicle does not turn around on the spot but directly reverses and retreats, the rear wheels of the automatic guided vehicle can be used as the front wheels during the retreat process. If the automatic guided vehicle turns around on the spot, the front wheels of the automatic guided vehicle can still be used as the front wheels in the process of calculating the steering angle. After that, the Stanley algorithm is used to calculate the steering angle of the automatic guided vehicle during the retreat process. During the calculation process, it is necessary to select a section from the saved driving trajectory as the trajectory containing the target point in the Stanley algorithm so that the automatic guided vehicle can track it. In this way, a longer section can be selected from the saved driving trajectory as the trajectory containing the target point in the Stanley algorithm, so that the tracking motion has a higher smoothness. Of course, a shorter section can also be selected from the saved driving trajectory as the trajectory containing the target point in the Stanley algorithm, so that the tracking motion has a higher accuracy.

[0064] Exemplarily, the trajectory control method may also include: during the driving process of the automatic guided vehicle, if it is detected that the deviation distance of the automatic guided vehicle from the ideal driving trajectory is greater than a preset threshold, then it is determined that the automatic guided vehicle deviates from the ideal driving trajectory. That is, during the driving process of the automatic guided vehicle, the deviation distance of the automatic guided vehicle from the ideal driving trajectory can be detected in real time, and it is determined whether the detected deviation distance is greater than the preset threshold. If the detected deviation distance is greater than the preset threshold, it is determined that the automatic guided vehicle deviates from the ideal driving trajectory. If the detected deviation distance is not greater than the preset threshold, it means that the degree of deviation of the automatic guided vehicle from the ideal driving trajectory is not large, and the automatic guided vehicle may not be determined as deviating from the ideal driving trajectory, and the automatic guided vehicle continues to perform automatic navigation driving.

[0065] When detecting the deviation distance of the automatic guided vehicle from the ideal driving track, a variety of methods can be used, and specific settings can be made in combination with the type of the ideal driving track. Some methods are introduced as examples below.

[0066] Exemplary, reference Figure 6 When the ideal driving trajectory includes a magnetic stripe track represented by a magnetic stripe, a magnetic sensor can be provided on the automatic guided vehicle, and the magnetic sensor is used to sense the magnetic strength of the current position of the automatic guided vehicle. The navigation principle of the automatic guided vehicle using magnetic navigation is: the position of the automatic guided vehicle relative to the magnetic stripe track is judged by the magnetic strength sensed by multiple positions of the magnetic sensor. The greater the magnetic strength, the closer the automatic guided vehicle is to the magnetic stripe track; the smaller the magnetic strength, the farther the automatic guided vehicle is from the magnetic stripe track. Exemplarily, during the driving process of the automatic guided vehicle, the magnetic sensor can be controlled to sense the magnetic strength of the current position of the automatic guided vehicle in real time, and the deviation distance or whether the automatic guided vehicle deviates from the ideal driving trajectory can be determined based on the magnetic strength.

[0067] Exemplarily, during the driving process of the automatic guided vehicle, if it is detected that the deviation distance of the automatic guided vehicle from the ideal driving trajectory is greater than a preset threshold, then determining that the automatic guided vehicle deviates from the ideal driving trajectory may include: referring to Figure 7 , during the driving process of the automatic guided vehicle, the magnetic sensor is controlled to sense the magnetic strength; if the magnetic strength sensed by the magnetic sensor is less than the preset strength threshold, it is determined that the automatic guided vehicle deviates from the ideal driving trajectory. That is, in this embodiment, the indicator for detecting the deviation distance is equivalently replaced by the magnetic strength indicator sensed by the magnetic sensor, and the preset threshold is equivalently replaced by the preset strength threshold. If the magnetic strength sensed by the magnetic sensor on the automatic guided vehicle is less than the preset strength threshold, it means that the deviation distance of the automatic guided vehicle relative to the ideal driving trajectory is greater than the preset threshold, and it is determined that the automatic guided vehicle deviates from the ideal driving trajectory. In this embodiment, there is no need to set a distance sensor, and thus there is no need to set a reference object, which simplifies the difficulty of deviation detection and reduces costs.

[0068] Exemplarily, when the ideal driving trajectory includes a magnetic stripe track represented by a magnetic stripe and a magnetic sensor is provided on the automatic guided vehicle, in the process of controlling the automatic guided vehicle to retract to a position that does not deviate from the ideal driving trajectory according to the saved driving trajectory, it can be determined by means of the magnetic stripe track and the magnetic sensor whether the automatic guided vehicle retracts to a position that does not deviate from the ideal driving trajectory. An exemplary method is introduced as follows.

[0069] Exemplarily, in the process of controlling the automatic guided vehicle to retract to a position that does not deviate from the ideal driving trajectory according to the saved driving trajectory, the magnetic sensor can be controlled to sense the magnetic strength according to the saved driving trajectory, and the distance between the automatic guided vehicle and the magnetic strip track is detected by the magnetic strength sensed by the magnetic sensor. When the magnetic strength sensed by the magnetic sensor is not less than the preset strength threshold, it means that the automatic guided vehicle has retracted to a position that does not deviate from the ideal driving trajectory. At this time, the automatic guided vehicle can be controlled to stop retracting, and it is determined that the automatic guided vehicle retracts to a position that does not deviate from the ideal driving trajectory. Through the retraction of the automatic guided vehicle, the position before the automatic guided vehicle deviates from the ideal driving trajectory is returned. That is, during the retraction process, the automatic guided vehicle is assumed to retract according to the saved driving trajectory, but in the actual retraction process, it may not be able to accurately retract to the original position. In this embodiment, as long as the automatic guided vehicle retreats to a position where the magnetic strength sensed by the magnetic sensor is not less than the preset strength threshold, it means that the automatic guided vehicle can navigate and drive according to the magnetic stripe track again, and the automatic guided vehicle is deemed to have retreated to a position that does not deviate from the ideal driving track, stops retreating, and can re-track the magnetic stripe track for navigation and driving. This embodiment does not need to determine the target point for retreat in advance, which not only simplifies the amount of calculation. Moreover, even if there is an error in the saved driving track relative to the actual driving track, as long as the error is not particularly large, the automatic guided vehicle can be controlled to retreat to a position that does not deviate from the ideal driving track.

[0070] Exemplarily, in the process of controlling the automatic guided vehicle to retract to a position that does not deviate from the ideal driving trajectory according to the saved driving trajectory, if the magnetic force intensity sensed by the magnetic sensor is still less than the preset intensity threshold after the automatic guided vehicle retracts for a preset adjustment time, the automatic guided vehicle is controlled to stop retracting and an alarm signal is issued. That is, during the time when the automatic guided vehicle retracts according to the saved driving trajectory within the preset adjustment time, the magnetic force intensity sensed by the magnetic sensor is always less than the preset intensity threshold, and after the automatic guided vehicle retracts for a preset adjustment time, the magnetic force intensity sensed by the magnetic sensor is still less than the preset intensity threshold, indicating that the automatic guided vehicle has not retracted to the position of the magnetic stripe track. At this time, there may be interference factors such as excessive driving trajectory error, which causes the automatic guided vehicle to be unable to automatically retract to the ideal driving trajectory, and it is also difficult to retract to the ideal driving trajectory according to the saved driving trajectory in the future. In this case, the automatic guided vehicle can be controlled to stop retracting and an alarm signal is issued to the outside world. The types of alarm signals may include, but are not limited to, horns, voice alarms, flashing lights, etc., to alert staff members, who may then assist in resetting the automated guided vehicle to the ideal driving trajectory.

[0071] Exemplarily, when the ideal driving trajectory includes a ribbon track represented by a ribbon, a visual sensor may be provided on the automatic guided vehicle, and the visual sensor is configured to capture an image of the automatic guided vehicle in a preset direction. The navigation principle of the automatic guided vehicle using ribbon navigation is similar to the principle of magnetic navigation, and the difference is that the position is determined by the visual sensor. The visual sensor is used to capture an image of the automatic guided vehicle in a preset direction. For example, the visual sensor may capture an image directly in front of, directly behind, or directly below the automatic guided vehicle. If the position of the ribbon track in the image is within the preset image area, it means that the deviation of the automatic guided vehicle from the ribbon track is not large, that is, the deviation distance of the automatic guided vehicle from the ribbon track is not greater than the preset threshold. If the position of the ribbon track in the image is outside the preset image area, or there is no image of the ribbon track in the image captured by the visual sensor, it means that the deviation of the automatic guided vehicle from the ribbon track is large, that is, the deviation distance of the automatic guided vehicle from the ribbon track is greater than the preset threshold. Simply put, if there is no ribbon track in the image captured by the visual sensor, it means that the automatic guided vehicle has deviated from the ideal driving trajectory; if there is a ribbon track in the image captured by the visual sensor, but the ribbon track does not appear in the preset image area, it also means that the automatic guided vehicle has deviated from the ideal driving trajectory; if there is a ribbon track in the image captured by the visual sensor, and the ribbon track appears in the preset image area, it means that the automatic guided vehicle has not deviated from the ideal driving trajectory.

[0072] Exemplarily, during the driving process of the automatic guided vehicle, if it is detected that the deviation distance of the automatic guided vehicle from the ideal driving track is greater than a preset threshold, then determining that the automatic guided vehicle deviates from the ideal driving track may include: during the driving process of the automatic guided vehicle, controlling the visual sensor to capture an image of the automatic guided vehicle in a preset direction; if the position of the ribbon track in the image is outside the preset image area, then determining that the automatic guided vehicle deviates from the ideal driving track. That is, in this embodiment, the index for detecting the deviation distance is equivalently replaced by the index of the image captured by the visual sensor of the automatic guided vehicle in the preset direction, and the preset threshold is equivalently replaced by the preset image area in the image captured by the visual sensor. If there is no ribbon track in the image captured by the visual sensor on the automatic guided vehicle, it means that the deviation distance of the automatic guided vehicle from the ideal driving track is greater than the preset threshold, indicating that the automatic guided vehicle has deviated from the ideal driving track; if there is a ribbon track in the image captured by the visual sensor, but the ribbon track does not appear in the preset image area, it means that the deviation distance of the automatic guided vehicle from the ideal driving track is greater than the preset threshold, which also means that the automatic guided vehicle has deviated from the ideal driving track; if there is a ribbon track in the image captured by the visual sensor, and the ribbon track appears in the preset image area, it means that the deviation distance of the automatic guided vehicle from the ideal driving track is not greater than the preset threshold, indicating that the automatic guided vehicle has not deviated from the ideal driving track. In this embodiment, there is no need to set a distance sensor, and thus there is no need to set a reference object, which simplifies the difficulty of deviation detection and reduces costs.

[0073] Exemplarily, when the ideal driving trajectory includes a ribbon track represented by a ribbon and a visual sensor is provided on the automatic guided vehicle, in the process of controlling the automatic guided vehicle to retract to a position that does not deviate from the ideal driving trajectory according to the saved driving trajectory, it can be determined by means of the ribbon track and the visual sensor whether the automatic guided vehicle retracts to a position before deviating from the ideal driving trajectory. An exemplary method is introduced as follows.

[0074] Exemplarily, in the process of controlling the automatic guided vehicle to retreat to a position that does not deviate from the ideal driving trajectory according to the saved driving trajectory, the automatic guided vehicle can be controlled to retreat according to the saved driving trajectory, while also controlling the visual sensor to capture an image of the automatic guided vehicle in a preset direction, and detecting the distance of the automatic guided vehicle from the ribbon track by the position of the ribbon track in the image. When the position of the ribbon track in the image is within the preset image area, it means that the automatic guided vehicle has retreated to a position that does not deviate from the ideal driving trajectory. At this time, the automatic guided vehicle can be controlled to stop retreating, and it is determined that the automatic guided vehicle retreats to a position that does not deviate from the ideal driving trajectory. Through the retreat of the automatic guided vehicle, the position before the automatic guided vehicle deviates from the ideal driving trajectory is returned. That is, during the retreat process, the automatic guided vehicle is assumed to retreat according to the saved driving trajectory, but in the actual retreat process, it may not be able to accurately retreat to the original position. In this embodiment, as long as the automatic guided vehicle retracts to the position where the position of the ribbon track in the image captured by the visual sensor is within the preset image area, it means that the automatic guided vehicle can navigate and drive according to the ribbon track again, and the automatic guided vehicle is deemed to have retracted to a position that does not deviate from the ideal driving track, stops retracting, and can re-track the ribbon track for navigation and driving. This embodiment does not need to determine the target point for retraction in advance, which not only simplifies the amount of calculation. Moreover, even if there is an error in the saved driving track relative to the actual driving track, as long as the error is not particularly large, the automatic guided vehicle can be controlled to retract to a position that does not deviate from the ideal driving track.

[0075] Exemplarily, in the process of controlling the automatic guided vehicle to retract to a position that does not deviate from the ideal driving trajectory according to the saved driving trajectory, if the position of the ribbon track in the image is still outside the preset image area after the automatic guided vehicle retracts for a preset adjustment time, the automatic guided vehicle is controlled to stop driving and an alarm signal is issued. That is, when the time for the automatic guided vehicle to retract according to the saved driving trajectory is within the preset adjustment time, the position of the ribbon track in the image captured by the visual sensor is always outside the preset image area, and after the automatic guided vehicle retracts for a preset adjustment time, the position of the ribbon track in the image captured by the visual sensor is still outside the preset image area, indicating that the automatic guided vehicle has not retracted to the position of the magnetic stripe track. At this time, there may be interference factors such as excessive driving trajectory error, which causes the automatic guided vehicle to be unable to automatically retract to the ideal driving trajectory, and it is also difficult to retract to the ideal driving trajectory according to the saved driving trajectory in the future. In this case, the automatic guided vehicle can be controlled to stop retracting and an alarm signal can be issued to the outside world. The types of alarm signals may include, but are not limited to, horns, voice alarms, flashing lights, etc., to alert staff members, who may then assist in resetting the automated guided vehicle to the ideal driving trajectory.

[0076] In the various embodiments shown above, during the driving process of the automatic guided vehicle, the odometer data of the automatic guided vehicle is acquired in real time, and based on the odometer data, the driving trajectory of the automatic guided vehicle is determined, and the obtained driving trajectory is saved, that is, the driving trajectory of the automatic guided vehicle is memorized through the odometer data, and the driving route of the automatic guided vehicle is memorized, which facilitates real-time recording of the historical operation trajectory information of the automatic guided vehicle, and helps the automatic guided vehicle to perform applications such as but not limited to deviation correction.

[0077] In addition, an embodiment of the present application also provides a trajectory control device for an automatic guided vehicle, which includes: a storage medium and a processor, wherein a computer program executed by the processor is stored on the storage medium, and when the computer program is executed by the processor, the processor executes any one of the above-mentioned trajectory control methods for an automatic guided vehicle.

[0078] Figure 8 FIG. 1 is a schematic block diagram of a trajectory control device 100 for an automatic guided vehicle according to an embodiment of the present application. Figure 8 As shown, the trajectory control device 100 of the automatic guided vehicle according to the embodiment of the present application may include a storage medium 110 and a processor 120, the storage medium 110 stores a computer program executed by the processor 120, and when the computer program is executed by the processor 120, the processor 120 executes the trajectory control method of the automatic guided vehicle according to the embodiment of the present application described above. Those skilled in the art can understand the specific operation of the deployment device of the trajectory control device 100 of the automatic guided vehicle according to the embodiment of the present application in combination with the content of the foregoing text, and for the sake of brevity, it will not be repeated here.

[0079] The storage medium 110 may include, for example, a memory card of a smart phone, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disk read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

[0080] Furthermore, an embodiment of the present application further provides an automatic guided vehicle, which includes: any of the above-mentioned automatic guided vehicle trajectory control devices. The automatic guided vehicle may also include a guide vehicle body, which may specifically include components such as a frame, wheels, a power battery, and a transmission, and any of the above-mentioned automatic guided vehicle trajectory control devices is provided on the guide vehicle body. Exemplarily, the automatic guided vehicle may also be provided with devices such as, but not limited to, magnetic sensors and visual sensors to perform corresponding operations in the above-mentioned automatic guided vehicle trajectory control method.

[0081] The present invention has been described by the above embodiments, but it should be understood that the above embodiments are only for the purpose of example and description, and are not intended to limit the present invention to the scope of the described embodiments. In addition, it can be understood by those skilled in the art that the present invention is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of the protection claimed by the present invention. The protection scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A trajectory control method for an automatic guided vehicle, characterized in that: include: During the driving process of the automatic guided vehicle, obtaining odometer data of the automatic guided vehicle; The driving trajectory of the automatic guided vehicle is determined according to the odometer data, and the driving trajectory is saved.

2. The trajectory control method according to claim 1, characterized in that: The step of obtaining odometer data of the automatic guided vehicle during the driving of the automatic guided vehicle includes: During the driving of the automatic guided vehicle, obtaining the rotation speed of the left wheel and the rotation speed of the right wheel; The linear speed and angular speed of the automatic guided vehicle are determined according to the rotation speed, and the wheel spacing and wheel radius of the left wheel and the right wheel, and the linear speed and angular speed of the automatic guided vehicle are used as the odometer data.

3. The trajectory control method according to claim 2, characterized in that: Determining the driving trajectory of the automatic guided vehicle according to the odometer data includes: A driving trajectory of the automatic guided vehicle is drawn according to the linear velocity and angular velocity of the automatic guided vehicle.

4. The trajectory control method according to any one of claims 1 to 3, characterized in that: Also includes: When the automatic guided vehicle deviates from the ideal driving trajectory, the automatic guided vehicle is controlled to retreat to a position that does not deviate from the ideal driving trajectory according to the saved driving trajectory.

5. The trajectory control method according to claim 4, characterized in that: The step of controlling the automatic guided vehicle to retract to a position that does not deviate from the ideal driving trajectory according to the saved driving trajectory includes: Determining a steering angle of the automatic guided vehicle during a retreat process according to the saved driving trajectory; According to the steering angle, the automatic guided vehicle is controlled to track the saved driving trajectory and retreat.

6. The trajectory control method according to claim 4, characterized in that: Also includes: During the driving process of the automatic guided vehicle, if it is detected that the deviation distance of the automatic guided vehicle from the ideal driving trajectory is greater than a preset threshold, it is determined that the automatic guided vehicle deviates from the ideal driving trajectory.

7. The trajectory control method according to claim 6, characterized in that: The ideal driving track includes a magnetic track represented by a magnetic strip, and a magnetic sensor is provided on the automatic guided vehicle; During the driving process of the automatic guided vehicle, if it is detected that the deviation distance of the automatic guided vehicle from the ideal driving trajectory is greater than a preset threshold, determining that the automatic guided vehicle deviates from the ideal driving trajectory includes: During the driving process of the automatic guided vehicle, controlling the magnetic force intensity of the magnetic sensor; If the magnetic force intensity sensed by the magnetic sensor is less than a preset intensity threshold, it is determined that the automatic guided vehicle deviates from the ideal driving trajectory.

8. The trajectory control method according to claim 7, characterized in that: The step of controlling the automatic guided vehicle to retract to a position that does not deviate from the ideal driving trajectory according to the saved driving trajectory includes: According to the saved driving track, the automatic guided vehicle is controlled to retreat, and the magnetic sensor senses the magnetic force intensity; When the magnetic force intensity sensed by the magnetic sensor is not less than the preset intensity threshold, the automatic guided vehicle is controlled to stop retreating, and the automatic guided vehicle is determined to retreat to a position that does not deviate from the ideal driving trajectory.

9. The trajectory control method according to claim 8, characterized in that: The step of controlling the automatic guided vehicle to return to a position that does not deviate from the ideal driving trajectory according to the saved driving trajectory further includes: If the magnetic force intensity sensed by the magnetic sensor is still less than the preset intensity threshold after the automatic guided vehicle has retreated for a preset adjustment time, the automatic guided vehicle is controlled to stop retreating and an alarm signal is issued.

10. The trajectory control method according to claim 6, characterized in that: The ideal driving trajectory includes a ribbon trajectory represented by a ribbon, and the automatic guided vehicle is provided with a visual sensor, and the visual sensor is configured to capture an image of the automatic guided vehicle in a preset direction; During the driving process of the automatic guided vehicle, if it is detected that the deviation distance of the automatic guided vehicle from the ideal driving trajectory is greater than a preset threshold, determining that the automatic guided vehicle deviates from the ideal driving trajectory includes: During the driving process of the automatic guided vehicle, controlling the visual sensor to capture an image of the automatic guided vehicle in a preset direction; If the position of the ribbon track in the image is outside the preset image area, it is determined that the automatic guided vehicle deviates from the ideal driving track.

11. The trajectory control method according to claim 10, characterized in that: The step of controlling the automatic guided vehicle to retract to a position that does not deviate from the ideal driving trajectory according to the saved driving trajectory includes: According to the saved driving trajectory, while controlling the automatic guided vehicle to retreat, the visual sensor is also controlled to capture an image of the automatic guided vehicle in a preset direction; When the position of the ribbon track in the image is within the preset image area, the automatic guided vehicle is controlled to stop retreating, and it is determined that the automatic guided vehicle retreats to a position that does not deviate from the ideal driving track.

12. The trajectory control method according to claim 11, characterized in that: The step of controlling the automatic guided vehicle to return to a position that does not deviate from the ideal driving trajectory according to the saved driving trajectory further includes: If the position of the ribbon track in the image is still outside the preset image area after the automatic guided vehicle has retreated for a preset adjustment time, the automatic guided vehicle is controlled to stop and an alarm signal is issued.

13. A trajectory control device for an automatic guided vehicle, characterized in that: include: A storage medium and a processor, wherein the storage medium stores a computer program executed by the processor, and when the computer program is executed by the processor, the processor executes the trajectory control method of an automatic guided vehicle according to any one of claims 1 to 12.

14. An automatic guided vehicle, characterized in that: include: The trajectory control device of the automatic guided vehicle as claimed in claim 13.

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