Loader bucket control method, apparatus, system, and unmanned loader

Abstract

The present application relates to the technical field of loader digging technology, and discloses a loader bucket control method, device, system and unmanned loader. When the loader bucket cuts into the material, the torque of the loader bucket is increased until the maximum torque, and the speed of the loader bucket is reduced to zero. If the speed of the loader bucket is zero and the torque of the loader bucket is the maximum torque, the state is maintained for a certain time. Based on the relationship curve between the angle of the loader bucket and the torque of the bucket, the loader bucket is controlled to perform the bucket collecting operation, which can prevent the bucket from being inserted into the material at a shallow position, so that the full bucket condition cannot be achieved. According to the actual angle of the bucket, the torque of the chassis is dynamically distributed to ensure the full bucket rate during the bucket digging process. When the loader bucket is parallel to the loader arm during the bucket collecting process, the torque of the loader bucket is controlled to be zero, so that the chassis does not apply torque after the bucket is collected, and the safety of the vehicle after the bucket is collected is ensured.

Description

Technical Field

[0001] This invention relates to the field of loader excavation technology, specifically to a loader bucket control method, device, system, and unmanned loader. Background Technology

[0002] In unmanned operation of loaders, the safety and bucket fullness of the digging process are directly related to the project progress and economic benefits. How to effectively coordinate bucket control and chassis control to complete the digging operation is a challenge. Most existing automatic digging control schemes are based on judging vehicle speed and torque, ignoring the actual state of the bucket and failing to guarantee the bucket fullness. Alternatively, they control the bucket to rotate alternately at preset times, keeping the bucket vibrating to ensure the fullness, but this causes significant vibration to the entire vehicle body. Existing automatic digging schemes do not involve coordinated control of the bucket and chassis, making it impossible to coordinate the movement of the bucket and chassis to ensure both fullness and safety. Summary of the Invention

[0003] In view of this, the present invention provides a loader bucket control method, device, system and unmanned loader to solve the problem that the bucket and chassis cannot move in coordination, which cannot guarantee the full bucket rate and the safety of the loader.

[0004] In a first aspect, the present invention provides a loader bucket control method, the method comprising: controlling the loader bucket to cut into material at a first speed, increasing the torque of the loader bucket up to the maximum torque, so that the speed of the loader bucket drops from the first speed to zero, and controlling the loader bucket to be perpendicular to the loader boom during this process; if the state of the loader bucket speed being zero and the loader bucket torque being at the maximum torque is maintained for a preset time threshold, based on the relationship curve between the angle of the loader bucket and the loader boom and the bucket torque, controlling the loader bucket to perform a bucket retraction operation, so that when the loader bucket is parallel to the loader boom, the torque of the loader bucket is zero.

[0005] The loader bucket control method provided by this invention increases the torque of the loader bucket until it reaches its maximum torque when the loader bucket cuts into the material, and then reduces the speed of the loader bucket to zero. If the speed of the loader bucket is zero and the torque of the loader bucket is at its maximum torque for a certain period of time, the loader bucket is controlled to retract based on the relationship curve between the angle of the loader bucket and the loader boom and the bucket torque. This can prevent situations where inaccurate slag detection leads to the bucket not inserting into the material, resulting in digging failure, or the bucket inserting into the material too shallowly, resulting in the bucket not being full. Furthermore, the chassis torque is dynamically distributed according to the actual angle of the bucket to ensure the full bucket rate during the digging process. During the bucket retraction process, when the loader bucket is parallel to the loader boom, the torque of the loader bucket is controlled to be zero to ensure that the chassis no longer applies torque after the bucket is retracted, thus ensuring the safety of the vehicle after the bucket is retracted.

[0006] In one optional implementation, the relationship curve between the angle of the loader bucket and the loader boom and the bucket torque is obtained through the following steps: selecting the loader bucket torque corresponding to any two angles formed between the loader bucket and the boom during the bucket retraction process as dynamic adjustment points, wherein the selected angles are greater than 0° and less than 90°; based on the maximum torque when the loader bucket is perpendicular to the boom, the zero torque when the loader is parallel to the boom, and the changing trend of the third-order Bezier curve adjusted by the two dynamic adjustment points, the relationship curve between the angle of the loader bucket and the loader boom and the bucket torque is obtained.

[0007] This invention selects the torque of the loader bucket corresponding to any two angles formed between the loader bucket and the boom as dynamic adjustment points, and adjusts the trend of the third-order Bézier curve based on the two endpoints of the maximum torque when the loader bucket is perpendicular to the boom and the zero torque when the loader is parallel to the boom. The third-order Bézier curve can be drawn into a more accurate smooth curve based on four control points, thereby obtaining a more accurate curve of the relationship between the angle of the loader bucket and the boom and the bucket torque, thus ensuring the safety of the bucket operation and the smoothness of the digging process.

[0008] In one optional implementation, controlling the loader bucket to retract based on the relationship curve between the angles of the loader bucket and the loader boom and the bucket torque includes: extracting a series of Bézier curve points from the relationship curve to form a set of Bézier curve points; obtaining the current angles of the loader bucket and the loader boom, and determining whether the current angle is consistent with any Bézier curve point in the set of Bézier curve points; if the current angle is consistent with a certain Bézier curve point in the set of Bézier curve points, then controlling the loader bucket to retract based on the first torque corresponding to the Bézier curve point consistent with the current angle; if the current angle is inconsistent with all Bézier curve points in the set of Bézier curve points, then selecting the torques corresponding to the two closest points to the current angle in the set of Bézier curve points, performing linear interpolation to obtain the second torque corresponding to the current angle, and controlling the loader bucket to retract based on the second torque.

[0009] The third-order Bézier curve of this invention is applied in practice through a series of discrete Bézier curve points. After extracting a series of Bézier curve points based on the relationship curve, the current angle between the loader bucket and the boom can be obtained during the bucket retraction process. If the current angle is inconsistent with all Bézier curve points, the torque corresponding to the two points closest to the current angle in the set of Bézier curve points is selected and linear interpolation is performed to obtain the second torque corresponding to the current angle. This prevents the actual angle value from not corresponding to a series of Bézier curve points, which would lead to errors in controlling the bucket torque and make it impossible to guarantee the safety and full bucket rate of the loader.

[0010] In an optional implementation, the method further includes: setting a safety point based on the material location point; and controlling the torque of the loader bucket to zero if, during the loader bucket retraction process, the current position of the loader bucket exceeds the safety point, or if the loader bucket is monitored to be parallel to the loader boom.

[0011] This invention sets a safety point at the material location. When the current position of the bucket exceeds the safety point, the torque of the bucket is controlled to zero. This prevents the loader from mistakenly detecting the presence of material when there is no material between the material location point and the safety point. In the absence of any resistance, the loader may apply a large torque, which could cause safety problems.

[0012] In an optional implementation, the method further includes: monitoring the roll angle and pitch angle of the loader, and controlling the loader to perform braking operation when the roll angle of the loader is greater than a preset roll angle threshold, and / or when the pitch angle of the loader is greater than a preset pitch angle threshold.

[0013] This invention monitors the loader's roll and pitch angles in real time and compares them with corresponding thresholds. If the angles exceed the thresholds, the loader is controlled to brake suddenly, ensuring the loader's safety.

[0014] In one optional implementation, before controlling the loader bucket to cut into the material at a first speed, the method further includes: setting a starting working point for the loader, obtaining the distance between the starting working point of the loader and the material location point, wherein the speed of the loader at the starting working point is zero; calculating the acceleration of the loader based on the first speed and the distance between the starting working point of the loader and the material location point; controlling the loader to travel based on the acceleration, and controlling the bucket to stay close to the ground during the loader's travel.

[0015] This invention sets a starting working point, obtains acceleration based on a first speed, the starting working point, and the material location, and controls the loader's movement to ensure that the loader has a certain speed at the material location, thus ensuring a high bucket full rate. Furthermore, by controlling the bucket to stay close to the ground during the loader's movement, it pushes residual material on the travel route to the material pile and excavates and collects the bucket at the material location.

[0016] In an optional implementation, the method further includes: when the loader travels from the parking point to the starting work point in tracking mode, switching the control mode of the loader from tracking mode to operation mode.

[0017] In a second aspect, the present invention provides a loader bucket control device, the device comprising:

[0018] The bucket control module is used to control the loader bucket to cut into the material at a first speed, increase the torque of the loader bucket until the maximum torque, so that the speed of the loader bucket drops from the first speed to zero, and during this process, control the loader bucket to be perpendicular to the loader boom.

[0019] The bucket retraction module is used to control the loader bucket to retract when the speed of the loader bucket is zero and the torque of the loader bucket is at its maximum for a period of time that reaches a preset time threshold. This is based on the relationship curve between the angle of the loader bucket and the loader boom and the bucket torque, so that the torque of the loader bucket is zero when the loader bucket is parallel to the loader boom.

[0020] Thirdly, the present invention provides a loader bucket control system, comprising: 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 computer instructions to perform the loader bucket control method of the first aspect or any corresponding embodiment described above.

[0021] Fourthly, the present invention provides an unmanned loader, including the loader bucket control system described in the third aspect above. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a flowchart illustrating the loader bucket control method according to an embodiment of the present invention;

[0024] Figure 2a This is an example diagram illustrating the speed change during the torque increase phase when a loader cuts into material according to an embodiment of the present invention;

[0025] Figure 2b This is an example diagram illustrating the torque variation during the torque increase phase when a loader cuts into material according to an embodiment of the present invention;

[0026] Figure 3 This is a flowchart illustrating another loader bucket control method according to an embodiment of the present invention;

[0027] Figure 4 This is an example diagram showing the changes in bucket angle and torque during the bucket retraction and forward movement according to an embodiment of the present invention.

[0028] Figure 5 It is a Bezier curve of bucket angle and torque according to an embodiment of the present invention;

[0029] Figure 6 This is a flowchart illustrating another loader bucket control method according to an embodiment of the present invention;

[0030] Figure 7 This is a schematic diagram of the overall process of automatic excavation by a loader according to an embodiment of the present invention;

[0031] Figure 8 This is a schematic diagram of the automatic excavation process of section AB by a loader according to an embodiment of the present invention;

[0032] Figure 9 This is a flowchart illustrating a three-stage automatic digging process according to an embodiment of the present invention;

[0033] Figure 10 This is a structural block diagram of the loader bucket control system according to an embodiment of the present invention;

[0034] Figure 11This is a structural block diagram of an unmanned loader according to an embodiment of the present invention;

[0035] Figure 12 This is a structural example diagram of a loader according to an embodiment of the present invention;

[0036] Figure 13 This is a structural block diagram of a loader bucket control device according to an embodiment of the present invention;

[0037] Figure 14 This is a schematic diagram of the hardware structure of the controller according to an embodiment of the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] In unmanned operation of loaders, the safety and bucket fullness of the digging process directly affect the project progress and economic benefits. A key challenge is how to effectively coordinate bucket control and chassis control during digging to complete the operation. Current engineering applications rarely involve coordinated control strategies for the loader's chassis and bucket to improve efficiency and safety. Most existing automatic digging control schemes rely on judging vehicle speed and torque, neglecting the actual bucket condition and failing to guarantee a full bucket rate. Alternatively, they control the bucket to rotate alternately at preset times, maintaining vibration to ensure a full bucket rate, but this causes significant vibration to the entire vehicle body. Existing automatic digging schemes do not involve coordinated control of the bucket and chassis, failing to ensure both a full bucket rate and safety through coordinated movement.

[0040] According to an embodiment of the present invention, a loader bucket control method is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0041] This embodiment provides a loader bucket control method, which can be used in the aforementioned controller. Figure 1 This is a flowchart of a loader bucket control method according to an embodiment of the present invention, such as... Figure 1 As shown, the process includes the following steps:

[0042] Step S101: Control the loader bucket to cut into the material at a first speed, increase the torque of the loader bucket until the maximum torque, so that the speed of the loader bucket drops from the first speed to zero, and during this process, control the loader bucket to be perpendicular to the loader boom.

[0043] In this embodiment of the invention, the speed of the loader bucket at the material location point is controlled as a first speed to ensure the bucket's fullness. The first speed is not limited and can be flexibly adjusted according to the type and density of the excavated material. The first speed can be set as a configuration file for easy debugging. When the loader bucket begins to excavate material, the material and the bucket will compress, causing the loader's speed to drop to zero. Simultaneously, a torque, also known as a moment, is applied to the loader chassis. This torque is ultimately transmitted from the chassis to the bucket end. The torque applied to the bucket end can be a tangential force to ensure that the material diagonally above the bucket falls into the bucket. The torque is controlled to increase from zero to the maximum torque F. max This ensures that as much material as possible falls into the bucket during the bucket-closing process, and that the loader bucket can be controlled to be perpendicular to the loader boom when the loader starts digging material, making it easier for material to fall into the bucket.

[0044] In specific embodiments, such as Figure 2a As shown, when the loader bucket begins to cut into the material, the bucket speed is zero due to the compression between the material and the bucket. Figure 2b As shown, torque is applied to the loader bucket, and the torque of the loader bucket is determined by F. min Gradually increase to F max As the torque of the loader bucket gradually increases, the excavator will accelerate to some extent with the increase in torque, but as the torque increases to F... max If it remains unchanged, the loader's speed will drop to zero due to the compression of the material.

[0045] Step S102: If the speed of the loader bucket is zero and the torque of the loader bucket is at its maximum for a period of time that reaches a preset time threshold, based on the relationship curve between the angle of the loader bucket and the loader boom and the bucket torque, the loader bucket is controlled to retract so that the torque of the loader bucket is zero when the loader bucket is parallel to the loader boom.

[0046] like Figure 2a and 2b As shown in the embodiment of the present invention, if the speed of the loader bucket is zero and the torque of the loader bucket is at its maximum, and the state is maintained for a preset time threshold, it indicates that the loader bucket has penetrated a relatively deep part of the material, and the bucket retraction operation can be performed. The preset time threshold can be represented by Δt, and its setting value can be set according to actual needs. If a full bucket rate is to be guaranteed, a larger time threshold can be set; if digging efficiency is to be guaranteed, a smaller time threshold can be set. There is no limitation.

[0047] In this embodiment of the invention, the relationship curve between the angle of the loader bucket and the loader boom and the bucket torque can be determined through multiple bucket retraction simulation experiments. For example, the angle and maximum torque of the bucket and boom when the bucket begins to cut into the material, and the angle and zero torque of the bucket and boom when the bucket is retracted can be used as constant endpoint variables. Then, based on the same angle between the bucket and the boom, different torque values ​​can be set to obtain the bucket full rate. The angle and torque value corresponding to the maximum bucket full rate can be selected as variable points. Then, based on the two constant endpoint variables and the variable points corresponding to the maximum bucket full rate, the least squares method or other algorithms can be used to perform curve fitting to obtain the relationship curve with the angle as the abscissa and the torque as the ordinate. Among them, when the bucket is retracted, that is, when the bucket is parallel to the boom, the torque applied to the bucket must be zero to ensure that the chassis no longer applies forward torque after the bucket is retracted, thus ensuring the safety of the vehicle after the bucket is retracted.

[0048] During the bucket retraction process, the angle between the bucket and the boom can be obtained in real time to obtain the corresponding torque, and the obtained torque can be applied to the bucket end to ensure that the torque of the loader bucket is zero when the loader bucket is parallel to the boom. The angle between the loader bucket and the boom can be obtained by using an IMU1 sensor installed on the boom and an IMU2 sensor installed on the bucket to obtain the angle information θ between the bucket and the boom. This is just an example.

[0049] The loader bucket control method provided by this invention involves increasing the loader bucket torque to its maximum when the bucket cuts into the material, reducing the bucket speed to zero. If the bucket speed is zero and the bucket torque is at its maximum for a certain period, the loader bucket is then controlled to retract based on the relationship curve between the angle of the loader bucket and the loader boom and the bucket torque. This prevents inaccurate slag detection from causing the bucket to fail to insert into the material, resulting in excavation failure, or the bucket to insert into the material too shallowly, leading to an inability to fill the bucket completely. Furthermore, the chassis torque is dynamically distributed according to the actual angle of the bucket to ensure a full bucket rate during the excavation process. During the bucket retraction process, when the loader bucket is parallel to the loader boom, the loader bucket torque is controlled to be zero to ensure that the chassis no longer applies torque after the bucket is retracted, thus ensuring vehicle safety after the bucket is retracted.

[0050] This embodiment provides a loader bucket control method, which can be used in the aforementioned controller. Figure 3 This is a flowchart of a loader bucket control method according to an embodiment of the present invention, such as... Figure 3 As shown, the process includes the following steps:

[0051] Step S301: Control the loader bucket to cut into the material at a first speed, increase the torque of the loader bucket until the maximum torque is reached, so that the speed of the loader bucket drops from the first speed to zero, and during this process, control the loader bucket to be perpendicular to the loader boom. For details, please refer to... Figure 1 Step S101 of the illustrated embodiment will not be described again here.

[0052] Step S302: If the speed of the loader bucket is zero and the loader bucket torque is at its maximum torque for a period of time that reaches a preset time threshold, based on the relationship curve between the angle of the loader bucket and the loader boom and the bucket torque, the loader bucket is controlled to retract so that the loader bucket torque is zero when the loader bucket is parallel to the loader boom.

[0053] Specifically, step S302 includes:

[0054] Step S3021: Select the torque of the loader bucket corresponding to any two angles formed between the loader bucket and the boom during the bucket retraction process as the dynamic adjustment point, wherein the selected angle is greater than 0° and less than 90°.

[0055] Step S3022: Based on the maximum torque when the loader bucket is perpendicular to the boom, the zero torque when the loader is parallel to the boom, and the changing trend of the third-order Bezier curve adjusted by the two dynamic adjustment points, obtain the relationship curve between the angle between the loader bucket and the loader boom and the bucket torque.

[0056] This invention embodiment can use a third-order Bézier curve to represent the relationship between torque and the angle between the loader bucket and the boom, without limitation. Second-, fourth-, or fifth-order Bézier curves can also be used, without limitation. For an n-order Bézier curve, n-1 control points and two endpoints need to be selected. This invention embodiment uses a third-order Bézier curve as an example, so two control points and two endpoints can be selected. The two endpoints can be the maximum torque when the loader bucket is perpendicular to the boom and the zero torque when the loader is parallel to the boom. The two control points can be selected based on actual debugging experience. Multiple tests are conducted using different bucket-boom angles and corresponding torques, and the two optimal points (i.e., the two points with the highest bucket fullness) are selected as control points. The angle between the loader bucket and the boom should be greater than 0° and less than 90°. Figure 4 As shown, the two endpoints are (θ1, f1) and (θ4, f4), and the two control points are (θ2, f2) and (θ3, f3). The corresponding torque angles are as follows: Figure 4 As shown, f1 and f4 are the maximum torques F. max F min =0, which will not be elaborated further here. By adjusting the trend of the third-order Bézier curve using two control points and two endpoints, the following can be obtained: Figure 5 The third-order Bezier curves of the angle and torque between the bucket and the boom shown are for illustrative purposes only.

[0057] This invention selects the torque of the loader bucket corresponding to any two angles formed between the loader bucket and the boom as dynamic adjustment points, and adjusts the trend of the third-order Bézier curve based on the two endpoints of the maximum torque when the loader bucket is perpendicular to the boom and the zero torque when the loader is parallel to the boom. The third-order Bézier curve can be drawn into a more accurate smooth curve based on four control points, thereby obtaining a more accurate curve of the relationship between the angle between the loader bucket and the boom and the bucket torque, thus ensuring the safety of the bucket operation.

[0058] Step S3023: Extract a series of Bézier curve points from the curve relating the angle between the loader bucket and the loader boom to the bucket torque, and form a set of Bézier curve points.

[0059] Step S3024: Obtain the current angle between the loader bucket and the loader boom, and determine whether the current angle is consistent with any Bézier curve point in the set of Bézier curve points.

[0060] Step S3025: If the current angle is consistent with a certain Bézier curve point in the set of Bézier curve points, then the loader bucket is controlled to perform a bucket retraction operation based on the first torque corresponding to the Bézier curve point that is consistent with the current angle.

[0061] Step S3026: If the current angle is inconsistent with all Bézier curve points in the set of Bézier curve points, select the torque corresponding to the two points closest to the current angle in the set of Bézier curve points, perform linear interpolation to obtain the second torque corresponding to the current angle, and control the loader bucket to perform bucket retraction operation based on the second torque.

[0062] In this embodiment of the invention, since the Bézier curve in practical applications consists of a series of discrete Bézier curve points, after obtaining the third-order Bézier curve of the angle and torque between the bucket and the boom, a series of Bézier curve points can be extracted to form a set of Bézier curve points. During the bucket retraction process, the angle between the loader bucket and the boom is acquired in real time through an IMU sensor. Then, based on the real-time acquired angle, the corresponding torque is obtained from the set of Bézier curve points to control the bucket to dig materials. For example, at time t, the bucket angle is calculated as θ using IMU sensor data. t Determine θ t If the angle is consistent with any Bézier curve point in the set of Bézier curve points, the torque control loader bucket corresponding to the Bézier curve point that matches the current angle can be directly selected for bucket retraction operation. If the current angle θ t If none of the points in the set of Bézier curve points are consistent with those in the set of Bézier curve points, then it can be like this: Figure 5 As shown, the x-coordinate distance θ is searched among the points on the Bézier curve. t The two closest points p1 and p2 can then be used for linear interpolation to calculate θ.t The corresponding torque f t Based on the calculated torque, the loader bucket is controlled to retract, and the torque f is applied. t The action is applied to the chassis, and when the actual angle of the bucket is greater than or equal to θ4, feedback indicates that the bucket retraction is complete. This is just an example.

[0063] The third-order Bézier curve of this invention is applied in practice through a series of discrete Bézier curve points. After extracting a series of Bézier curve points based on the relationship curve, the current angle between the loader bucket and the boom can be obtained during the bucket retraction process. If the current angle is inconsistent with all Bézier curve points, the torque corresponding to the two points closest to the current angle in the set of Bézier curve points is selected and linear interpolation is performed to obtain the second torque corresponding to the current angle. This prevents the actual angle value from not corresponding to a series of Bézier curve points, which would lead to errors in controlling the bucket torque and make it impossible to guarantee the safety and full bucket rate of the loader.

[0064] This embodiment provides a loader bucket control method, which can be used in the aforementioned controller. Figure 6 This is a flowchart of a loader bucket control method according to an embodiment of the present invention, such as... Figure 6 As shown, the process includes the following steps:

[0065] Step S601: When the loader travels from the parking point to the starting work point in tracking mode, the control mode of the loader is switched from tracking mode to operation mode.

[0066] like Figure 7 As shown, this embodiment of the invention divides the loader's excavation control process into three stages. Point O is the loader's parking point. At the parking point, the loader's working module is set to line-following mode. It follows the line to point A, the starting point, and then switches the loader's control mode from line-following mode to working mode. This is merely an example. The AC-section shoveling scheme in this embodiment is divided into three stages: AB section: ground-hugging rapid advance; transition section: torque increase; and shoveling section: bucket retraction and forward movement. This three-stage automatic shoveling control process covers most scenarios of unmanned loader operations and has strong versatility.

[0067] Step S602: Set the starting working point of the loader, obtain the distance between the starting working point of the loader and the material position point, and the speed of the loader is zero at the starting working point; calculate the acceleration of the loader based on the first speed and the distance between the starting working point of the loader and the material position point; control the loader to travel based on the acceleration, and control the bucket to keep it close to the ground during the loader's travel.

[0068] like Figure 8As shown, in this embodiment of the invention, point A is the starting working point of the loader. The bucket control module can control the bucket to stay close to the ground. The lidar on the top of the loader is responsible for detecting the material distribution and providing the material location point B. The vehicle material detection module obtains the distance x1 of segment AB. Point B can be the slag, i.e., the material entry point. Because a high bucket full rate needs to be ensured during the digging process, a certain entry speed can be set at point B, denoted as v. b Let the velocity at point A be v. a Generally v a =0, for example only. The acceleration of the loader can be calculated by following these steps:

[0069] v b 2 -v a 2 =2a1x1

[0070] Where a1 represents the acceleration of the loader.

[0071] In this embodiment of the invention, after obtaining the loader's driving acceleration, the vehicle torque output at acceleration a1 can be obtained by linear interpolation from the torque calibration table. This torque is then sent to the chassis drive motor, which controls the loader to travel to point B based on the torque and acceleration. As an example, the remaining material in section AB is pushed to the material pile, and the bucket is shoveled and filled. After the bucket is full, the loader returns to point A, thus completing one shoveling operation.

[0072] In a specific embodiment, a maximum speed V can also be set in segment AB. abmax The maximum speed is determined based on the actual site conditions and there's no specific calculation method. It's simply a speed protection setting, which can be set to 2-3 m / s depending on the actual situation. This is just an example; during the loader's movement in section AB, the loader's speed is monitored. When the monitored speed exceeds V... abmax The chassis torque can be released to reduce the loader's speed and prevent loss of control, allowing it to enter the slag entry point with greater momentum and ensuring safety. This is just an example.

[0073] This invention sets a starting working point, obtains acceleration based on a first speed, the starting working point, and the material location, and controls the loader's movement to ensure that the loader has a certain speed at the material location, thus ensuring a high bucket full rate. Furthermore, by controlling the bucket to stay close to the ground during the loader's movement, it pushes residual material on the travel route to the material pile and excavates and collects the bucket at the material location.

[0074] Step S603: Control the loader bucket to cut into the material at a first speed, increase the torque of the loader bucket until the maximum torque is reached, so that the speed of the loader bucket drops from the first speed to zero, and during this process, control the loader bucket to be perpendicular to the loader boom. For details, please refer to [link to details]. Figure 3 Step S301 of the illustrated embodiment will not be described again here.

[0075] Step S604: If the monitored state of zero speed and maximum torque of the loader bucket is maintained for a preset time threshold, based on the relationship curve between the angle of the loader bucket and the loader boom and the bucket torque, the loader bucket is controlled to retract, so that the loader bucket torque is zero when the loader bucket is parallel to the loader boom. For details, please refer to [link to relevant documentation]. Figure 3 Step S302 of the illustrated embodiment will not be described again here.

[0076] Step S605: Set a safety point based on the material location point; during the loader bucket retraction process, if the current position of the loader bucket is detected to exceed the safety point position, or if the loader bucket is monitored to be parallel to the loader boom, control the torque of the loader bucket to zero.

[0077] like Figure 8 As shown, a safety point C can be set based on the material location point B. Point C is on the extension of line segment AB. Based on actual experience in manual digging, a safety protection distance of 2-3m can be randomly selected from line segment BC as an example. This is not a limitation but just an example. During the bucket retraction process in section BC, starting from point B, when the travel distance exceeds the length of BC or the bucket has been retracted into place, the chassis torque is released to prevent the material detection module from mistakenly detecting the presence of material when there is no material in section BC. Applying a large torque by the loader without any resistance can cause safety problems.

[0078] This invention sets a safety point at the material location. When the current position of the bucket exceeds the safety point, the torque of the bucket is controlled to zero. This prevents the loader from mistakenly detecting the presence of material when there is no material between the material location point and the safety point. In the absence of any resistance, the loader may apply a large torque, which could cause safety problems.

[0079] Step S606: Monitor the roll angle and pitch angle of the loader. When the roll angle of the loader is greater than the preset roll angle threshold, and / or the pitch angle of the loader is greater than the preset pitch angle threshold, control the loader to perform a braking operation.

[0080] In this embodiment of the invention, during the loader's travel, digging and bucket retraction, and bucket retraction completion processes, the loader's roll and pitch angles can be obtained in real time using RTK (Realtimekinematic) technology. These angles can be based on multiple experiments or pre-set by experts to correspond to the loader's roll and pitch angle thresholds, respectively denoted as roll. t and pitch max When roll is detected t >roll max And / or, detected pitch t >pitch max In such cases, it is considered that the loader is at risk of overturning, and emergency braking of the loader can be controlled, which is only an example.

[0081] This invention monitors the loader's roll and pitch angles in real time and compares them with corresponding thresholds. If the angles exceed the thresholds, the loader is controlled to brake suddenly, ensuring the loader's safety.

[0082] In specific embodiments, such as Figure 9 As shown, when the loader travels to point A, the acceleration of segment AB is calculated, and the corresponding torque F is obtained using the calibration value of the torque table. F is then output to the chassis drive motor. When the loader travels from point A to point B, due to the compression of the material and the loader bucket, the loader's speed is zero due to resistance. An increasing torque is applied to the bucket until the maximum torque is reached. When the torque received by the bucket remains constant at the maximum torque, the bucket speed drops to 0. The system monitors whether the state of the bucket having the maximum torque and the vehicle speed being zero exceeds a limited time Δt. Based on the angle between the loader bucket and the boom and the corresponding torque, four control points are selected, namely two endpoints and two control points. A Bezier curve point sequence is calculated based on the four control points. During the bucket retraction process, the bucket angle θ is calculated in real time. t Based on bucket angle θ t Search for the nearest Bezier point, perform interpolation, and output the corresponding torque to control the bucket to retract. When θ t When the angle exceeds the set limit, feedback indicates that the bucket retraction is complete, and the loader is controlled to return to point A, indicating that the excavation task is complete.

[0083] This embodiment also provides a loader bucket control system, such as Figure 10 As shown, the system includes a controller 1001, which includes a memory and a processor. The memory and the processor are communicatively connected. The memory stores computer instructions, and the processor executes the computer instructions to perform the loader bucket control method described in the above embodiment. For a detailed description, please refer to the above embodiment; it will not be repeated here.

[0084] This embodiment also provides an unmanned loader, such as Figure 11 As shown, the unmanned loader includes the loader bucket control system 1101 described in the above embodiments. In a specific embodiment, as shown... Figure 12 As shown, the unmanned loader also includes a bucket, boom, IMU1, IMU2, cab, articulation point, and rear axle center, which are not limited and are only examples.

[0085] This embodiment also provides a loader bucket control device for implementing the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0086] This embodiment provides a loader bucket control device, such as... Figure 13 As shown, it includes:

[0087] The bucket control module 1301 is used to control the loader bucket to cut into the material at a first speed, increase the torque of the loader bucket until the maximum torque, so that the speed of the loader bucket drops from the first speed to zero, and control the loader bucket to be perpendicular to the loader boom during this process.

[0088] The bucket retraction module 1302 is used to control the loader bucket to retract when the speed of the loader bucket is zero and the torque of the loader bucket is at its maximum for a period of time that reaches a preset time threshold. This is based on the relationship curve between the angle of the loader bucket and the loader boom and the bucket torque, so that the torque of the loader bucket is zero when the loader bucket is parallel to the loader boom.

[0089] In some alternative implementations, the bucket collecting module 1302 includes:

[0090] The adjustment point selection unit is used to select the torque of the loader bucket corresponding to any two angles formed between the loader bucket and the boom during the bucket retraction process as a dynamic adjustment point. The selected angle is greater than 0° and less than 90°.

[0091] The curve acquisition unit is used to obtain the relationship curve between the angle between the loader bucket and the loader boom and the bucket torque, based on the maximum torque when the loader bucket is perpendicular to the boom, the zero torque when the loader is parallel to the boom, and the changing trend of the third-order Bezier curve adjusted by two dynamic adjustment points.

[0092] In some alternative implementations, the bucket collecting module 1302 includes:

[0093] The curve point extraction unit is used to extract a series of Bézier curve points from the curve relating the angle between the loader bucket and the loader boom to the bucket torque, forming a set of Bézier curve points.

[0094] The current angle acquisition unit is used to acquire the current angle between the loader bucket and the loader boom, and to determine whether the current angle is consistent with any Bézier curve point in the set of Bézier curve points;

[0095] The torque acquisition unit is used to control the loader bucket to perform a bucket retraction operation based on the first torque corresponding to the Bézier curve point that matches the current angle if the current angle matches a certain Bézier curve point in the set of Bézier curve points.

[0096] The torque interpolation processing unit is used to select the torques corresponding to the two points closest to the current angle in the Bézier curve point set if the current angle is inconsistent with all Bézier curve points in the set, and perform linear interpolation processing to obtain the second torque corresponding to the current angle, and control the loader bucket to perform bucket retraction operation based on the second torque.

[0097] In some optional implementations, the loader bucket control device further includes: a safety point setting module for setting a safety point based on the material location point; and a position monitoring module for controlling the torque of the loader bucket to zero if, during the loader bucket retraction process, the current position of the loader bucket exceeds the safety point position, or if the loader bucket is monitored to be parallel to the loader boom.

[0098] In some optional embodiments, the loader bucket control device further includes: a loader angle monitoring module for monitoring the loader's tilt angle and pitch angle, and controlling the loader to perform braking operation when the loader's tilt angle is greater than a preset tilt angle threshold and / or the loader's pitch angle is greater than a preset pitch angle threshold.

[0099] In some optional embodiments, the loader bucket control device further includes: a working point setting module, used to set the loader's starting working point and obtain the distance between the loader's starting working point and the material position point, wherein the loader's speed is zero at the starting working point; an acceleration calculation module, used to calculate the loader's acceleration based on the first speed and the distance between the loader's starting working point and the material position point; and a bucket travel control module, used to control the loader's travel based on the acceleration and control the bucket to stay close to the ground during the loader's travel.

[0100] In some optional implementations, the loader bucket control device further includes a working mode switching module, used to switch the loader's control mode from tracking mode to working mode when the loader travels from the parking point to the starting working point in tracking mode.

[0101] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0102] In this embodiment, the loader bucket control device is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0103] This invention also provides a controller having the above-described features. Figure 13 The loader bucket control device shown.

[0104] Please see Figure 14 , Figure 14 This is a schematic diagram of the structure of a controller provided in an optional embodiment of the present invention, such as... Figure 14 As shown, the controller includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise as required. The processors can process instructions executed within the controller, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple controllers can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 14 Take a processor 10 as an example.

[0105] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0106] The memory 20 stores instructions executable by at least one processor 10 to cause the at least one processor 10 to perform the method shown in the above embodiments.

[0107] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the controller. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, and these remote memories may be connected to the controller via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0108] The memory 20 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0109] The controller also includes an input device 30 and an output device 40. The processor 10, memory 20, input device 30, and output device 40 can be connected via a bus or other means. Figure 14 Taking the example of a connection between China and Israel via a bus.

[0110] Input device 30 can receive input digital or character information, and generate signal inputs related to user settings and function control of the controller, such as a touch screen, keypad, mouse, trackpad, touchpad, joystick, one or more mouse buttons, trackball, joystick, etc. Output device 40 may include display devices, auxiliary lighting devices (e.g., LEDs), and haptic feedback devices (e.g., vibration motors). The aforementioned display devices include, but are not limited to, liquid crystal displays, light-emitting diodes, displays, and plasma displays. In some alternative embodiments, the display device may be a touch screen.

[0111] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0112] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for controlling the bucket of a loader, characterized in that, The method includes: Control the loader bucket to cut into the material at a first speed, increase the torque of the loader bucket until the maximum torque, so that the speed of the loader bucket drops from the first speed to zero, and during this process, control the loader bucket to be perpendicular to the loader boom; If the speed of the loader bucket is zero and the torque of the loader bucket is at its maximum for a period of time that reaches a preset time threshold, the loader bucket will be controlled to retract based on the relationship curve between the angle of the loader bucket and the loader boom and the bucket torque, so that the torque of the loader bucket is zero when the loader bucket is parallel to the loader boom. The relationship curve between the angles of the loader bucket and the loader boom and the bucket torque is obtained through the following steps: The torque of the loader bucket corresponding to any two angles formed between the loader bucket and the boom during the bucket retraction process is selected as the dynamic adjustment point. The selected angles are greater than 0° and less than 90°. Based on the maximum torque when the loader bucket is perpendicular to the boom, the zero torque when the loader is parallel to the boom, and the changing trend of the third-order Bezier curve adjusted by two dynamic adjustment points, the relationship curve between the angle between the loader bucket and the loader boom and the bucket torque is obtained.

2. The loader bucket control method according to claim 1, characterized in that, The method of controlling the loader bucket to retract based on the relationship curve between the angle of the loader bucket and the loader boom and the bucket torque includes: A series of Bézier curve points are extracted from the curve relating the angle between the loader bucket and the loader boom to the bucket torque, forming a set of Bézier curve points; Obtain the current angle between the loader bucket and the loader boom, and determine whether the current angle is consistent with any Bézier curve point in the set of Bézier curve points; If the current angle is consistent with a certain Bézier curve point in the set of Bézier curve points, then the loader bucket is controlled to perform a bucket retraction operation based on the first torque corresponding to the Bézier curve point that is consistent with the current angle. If the current angle is inconsistent with all Bézier curve points in the set of Bézier curve points, the torque corresponding to the two points closest to the current angle in the set of Bézier curve points is selected, and linear interpolation is performed to obtain the second torque corresponding to the current angle. The loader bucket is then controlled to perform a bucket retraction operation based on the second torque.

3. The loader bucket control method according to claim 1, characterized in that, The method further includes: Set a safety point based on the material location point; During the loader bucket retraction process, if the current position of the loader bucket is detected to be beyond the safe point, or if the loader bucket is monitored to be parallel to the loader boom, the torque of the loader bucket will be controlled to zero.

4. The loader bucket control method according to claim 1, characterized in that, The method further includes: Monitor the roll angle and pitch angle of the loader. When the roll angle of the loader is greater than a preset roll angle threshold, and / or the pitch angle of the loader is greater than a preset pitch angle threshold, control the loader to perform a braking operation.

5. The loader bucket control method according to any one of claims 1-4, characterized in that, Before controlling the loader bucket to cut into the material at a first speed, the method further includes: Set the starting working point of the loader, and obtain the distance between the starting working point of the loader and the material location point. The speed of the loader is zero at the starting working point. Based on the first speed and the distance between the loader's starting point and the material's location, the loader's acceleration is calculated. The loader is controlled to travel based on the acceleration, and the bucket is controlled to stay close to the ground during the loader's travel.

6. The loader bucket control method according to claim 5, characterized in that, The method further includes: When the loader travels from the parking point to the starting work point using the tracking mode, the control mode of the loader is switched from tracking mode to operation mode.

7. A loader bucket control device, characterized in that, The loader bucket control device includes: The bucket control module is used to control the loader bucket to cut into the material at a first speed, increase the torque of the loader bucket until the maximum torque, so that the speed of the loader bucket drops from the first speed to zero, and during this process, control the loader bucket to be perpendicular to the loader boom. The bucket retraction module is used to control the loader bucket to retract when the monitored state of zero speed and maximum torque is maintained for a preset time threshold. This is based on the relationship curve between the angle of the loader bucket and the boom and the bucket torque, so that the loader bucket torque is zero when the loader bucket is parallel to the boom. The relationship curve between the angle of the loader bucket and the boom and the bucket torque is obtained through the following steps: selecting the loader bucket torque corresponding to any two angles formed between the loader bucket and the boom during the bucket retraction process as dynamic adjustment points, wherein the selected angles are greater than 0° and less than 90°; and adjusting the change trend of the third-order Bézier curve based on the maximum torque when the loader bucket is perpendicular to the boom, the zero torque when the loader is parallel to the boom, and the two dynamic adjustment points to obtain the relationship curve between the angle of the loader bucket and the boom and the bucket torque.

8. A loader bucket control system, characterized in that, The loader bucket control system includes: A controller, comprising a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, the processor executing the computer instructions to perform the loader bucket control method of any one of claims 1 to 6.

9. An unmanned loader, characterized in that, The unmanned loader includes the loader bucket control system as described in claim 8.

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