An excavator system and automated work method

Abstract

The application discloses a kind of excavator systems, including excavator body, vehicle-mounted inertial navigation system and automatic unloading control system are installed on excavator body, still include cloud data processing system, vehicle-mounted inertial navigation system and automatic unloading control system are connected with cloud data processing system communication;Vehicle-mounted inertial navigation system is used to collect the current coordinate information of excavator body, it is sent to cloud data processing system, cloud data processing system is handled by preset automatic operation algorithm, control signal is fed back to automatic unloading control system, and automatic unloading control system controls excavator body to execute control signal and then realizes automatic unloading operation, in combination with the compatible excavator automatic operation method, so that excavator completes automatic unloading operation, and driver is liberated from the burden of mechanical repetitive operation, saves manpower cost, improves production efficiency.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, specifically to an excavator and an automated loading / unloading method. Background Technology

[0002] Excavators are used in various engineering fields. Their motion structures are generally tracked or wheeled to adapt to complex working conditions, but this also brings with it a complex control system. An excavator typically consists of a motion device and a working device. The working device usually comprises a two-link robotic arm and a bucket, forming a three-degree-of-freedom motion system. With the increasing maturity of network communication technology, vehicle-to-everything (V2X) solutions are becoming more available. The excavator's working device has a complex transmission structure and operational complexity, which V2X and automatic control can simplify. The excavator's robotic arm is quite flexible. Due to the complex working environment, the operator's field of vision may have blind spots in certain situations. Combined booms offer flexibility, and automated unloading not only reduces the operator's workload but also avoids operational errors caused by blind spots. Generally, automated unloading requires the simultaneous coordinated movement of the boom, stick, and bucket, reducing the possibility of operational errors and lessening the operator's burden.

[0003] This invention relates to the working device of an excavator, including a robotic arm, a rotating chassis, and a bucket. It designs an automatic control algorithm so that when the operator fills the bucket with material, the excavator completes an automated unloading operation, thereby reducing the operator's workload. Summary of the Invention

[0004] The purpose of this invention is to provide an excavator system and an automated operation method to solve the problems mentioned in the background art, such as the complex transmission structure and operation complexity of the excavator working device, and the cumbersome excavator operation process and mechanical repetition leading to waste of human resources.

[0005] To achieve the above objectives, the present invention provides the following technical solution: An excavator system includes: an excavator body, on which an onboard inertial navigation system and an automated unloading control system are installed, and a cloud data processing system is also included. The onboard inertial navigation system and the automated unloading control system are communicatively connected to the cloud data processing system. The onboard inertial navigation system is used to collect the current coordinate information of the excavator body and send it to the cloud data processing system. The cloud data processing system processes the data through a preset automated operation algorithm and feeds back control signals to the automated unloading control system. The automated unloading control system controls the excavator body to execute control signals to achieve automated unloading operations.

[0006] As a preferred technical solution, the excavator body includes a lower body, a rotating chassis mounted on the lower body, a boom hinged to the upper end of the rotating chassis, a forearm hinged to the upper end of the boom, a bucket hinged to the end of the forearm, and a hydraulic transmission system. Sensors for measuring the joint movement angle are installed at each of the hinge points. Under the control of the automated unloading control system, the hydraulic transmission system drives the boom, forearm, and bucket to complete the unloading operation.

[0007] An automated excavator operation method includes the following steps:

[0008] Step S1: The cloud data processing system receives the real-time location of the excavator sent by the vehicle-mounted inertial navigation system and guides the driver to the material loading point to excavate materials;

[0009] Step S2: The excavator body determines whether the excavator is fully loaded. If it is fully loaded, the cloud data processing system sends a stop automatic loading operation command to the automatic unloading control system; automatic loading ends. If it is not fully loaded, the cloud data processing system sends a start automatic loading operation command and an operation movement path command planned according to the preset automatic operation algorithm to the automatic unloading control system, and controls the excavator body to complete the unloading operation at the cargo box position.

[0010] Step S3: The cloud data processing system sends the planned path to the automated unloading control system. After the excavator body arrives at the loading point, the driver performs the next material excavation.

[0011] As a preferred technical solution, the automated loading operation instruction includes forward kinematics calculation and inverse kinematics calculation. The forward kinematics calculation controls the rotation angle and rotation speed of each joint of the excavator's robotic arm, that is, the spatial coordinates of the joint variables of the excavator's robotic arm and the pose information of the corresponding connected end-cap bucket. Given the parameters of the excavator's robotic arm and the target angle of each joint, the position and attitude of the end-cap bucket are solved. The inverse kinematics calculation, knowing the position and attitude of the excavator bucket, reversely deduces the position and attitude of each joint of the excavator's robotic arm based on the parameters of the excavator's robotic arm.

[0012] As a preferred technical solution, the forward kinematics solution includes the following steps:

[0013] Step 1) Construct a mathematical model. Based on the characteristics of the excavator's robotic arm, simplify the system into a three-degree-of-freedom system. Let θ1 be the base rotation angle, θ2 be the boom movement angle, θ3 be the boom curvature angle (fixed), θ4 be the forearm movement angle, φ be the bucket movement angle, and a1, a2, and a3 be the excavator robotic arm length parameters. Establish the oxyz coordinate system as the base coordinate system of the working device.

[0014] Step 2) Based on the coordinates of the midpoint of the cargo box in the cloud, θ1, θ2, and θ4 are obtained through inverse calculation. θ3 is a fixed angle, and φ is the bucket unloading angle. When the target angle is reached, the angle is moved to its maximum. At this time, all the material in the bucket will be unloaded into the cargo box of the transport vehicle.

[0015] As a preferred technical solution, inverse kinematics calculation includes the following steps:

[0016] Step 3) Calculate the angle based on the simplified three-degree-of-freedom system. Assume the center coordinates of the loading point are at point A, and establish a coordinate system with the excavator as the origin; θ1 is the angle of rotation required for the excavator bucket to move to the loading point A, X is the distance from the loading point to the excavator, provided by inertial navigation positioning data, and Y is the excavator hardware parameter, i.e., the length of the robotic arm. θ1 is calculated as follows:

[0017]

[0018] Step 4) Calculate the motion angles of each joint of the robotic arm; let L1 be the length of the upper arm; L2 be the length of the lower arm; L3 be the distance from the center of the bucket to the connection point of the lower arm (a hardware constant); point A is the known midpoint of the cargo box of the transport vehicle; γ is the angle between L3 and the x-axis. From this point, deduce the motion angles of θ2, θ4, and φ; let the coordinates of point A be (x, y), then:

[0019] C x = x - L3 × Cos(γ)

[0020] C y = y - L3 × Sin(γ)

[0021]

[0022] Similarly, we can obtain the value of Cos(α) and then calculate θ2:

[0023]

[0024] Therefore, the value of the cosine of θ4 is:

[0025]

[0026] Therefore, the value of φ is:

[0027]

[0028] After calculating θ2, θ4, and φ, the excavator's robotic arm can move to automatically unload materials from the excavation area into the cargo box of the transport vehicle.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] An automatic control algorithm is designed for the excavator's working devices, including the robotic arm, rotating chassis, and bucket. When the operator fills the bucket with material, the excavator completes an automated unloading operation, thereby reducing the operator's workload. This automated unloading operation, combined with suitable excavator automation methods, frees the operator from repetitive mechanical tasks, saves labor costs, and improves production efficiency. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating the automated unloading process of the present invention.

[0032] Figure 2 This describes the process of the transport vehicle arriving at the work area in this invention;

[0033] Figure 3 To initiate the automated unloading process in this invention;

[0034] Figure 4 This is a schematic diagram of the excavator robotic arm structure in this invention;

[0035] Figure 5 This is the mathematical model of the excavator robotic arm in this invention;

[0036] Figure 6 This is a modeling diagram of the excavator robotic arm, i.e., the loading point, in this invention;

[0037] Figure 7 This is a diagram showing the joint angle relationships in the inverse kinematics solution of the excavator robotic arm motion planning in this invention;

[0038] Figure 8 The diagram shows the implementation of the Matlab simulation code;

[0039] Figure 9 This is a MATLAB simulation graph. Detailed Implementation

[0040] 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, and 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.

[0041] This invention provides a technical solution: an excavator system includes an excavator body, on which an onboard inertial navigation system and an automated unloading control system are installed, and a cloud data processing system is also included. The onboard inertial navigation system and the automated unloading control system are communicatively connected to the cloud data processing system. The onboard inertial navigation system collects the current coordinate information of the excavator body and sends it to the cloud data processing system. The cloud data processing system processes the data using a preset automated operation algorithm and feeds back control signals to the automated unloading control system. The automated unloading control system controls the excavator body to execute the control signals, thereby realizing automated unloading operations. The excavator body includes a lower body, a rotating chassis mounted on the lower body, a boom hinged to the upper end of the rotating chassis, a forearm hinged to the upper end of the boom, a bucket hinged to the end of the forearm, and a hydraulic transmission system. Sensors for calculating joint movement angles are installed at each hinge point. Under the control of the automated unloading control system, the hydraulic transmission system drives the boom, forearm, and bucket to complete the unloading operation. (See also...) Figure 4 1 and 2 together form the rotating chassis; 3 is the boom; 4 and 5 are the hydraulic systems that provide power to the boom; 6 is the forearm; 7 and 8 are the hydraulic systems that provide power to the forearm; 9, 10, and 11 are the hydraulic systems that provide power to the bucket; and 12 and 13 are the bucket movement linkages. The telescopic lengths of 5, 8, and 11 can be converted into boom movement angles, forming a closed loop with the angle sensors installed at the joint connections to ensure rotational accuracy.

[0042] Simultaneously, a method for automating excavator operations is provided and integrated into the excavator system. (See also...) Figure 3 It includes the following steps:

[0043] Step S1: The cloud data processing system receives the real-time location of the excavator sent by the vehicle-mounted inertial navigation system and guides the driver to the material loading point to excavate materials;

[0044] Step S2: The excavator body determines whether the excavator is fully loaded. If it is fully loaded, the cloud data processing system sends a full load signal to the cloud data processing system and sends a stop automatic loading operation command to the automatic unloading control system; automatic loading ends; if it is not fully loaded, the cloud data processing system sends a start automatic loading operation command and an operation movement path command planned according to the preset automatic operation algorithm to the automatic unloading control system, and controls the excavator body to complete the unloading operation at the cargo box position;

[0045] Step S3: The cloud data processing system sends the planned path to the loading point to the automated unloading control system, and the driver performs the next material excavation.

[0046] The following provides a detailed description of the control strategy, algorithm implementation, and simulation process.

[0047] The main vehicle coordinate information for automated unloading comes from the onboard inertial navigation system. The excavator sends its own coordinate information to the cloud, which is the excavator's coordinate system with reference to the world coordinate system. After receiving the coordinates, the cloud processes them and sends them to the transport vehicle that needs to load the material. The transport vehicle arrives at the excavator's loading area via the navigation system. After the transport vehicle parks and is ready to load, it sends its combined inertial navigation information to the cloud. This information includes coordinates with reference to the world coordinate system and the vehicle's heading angle. The cloud calculates the coordinates of the cargo box's midpoint using the vehicle's coordinates, heading angle, and dimensions, and sends these coordinates to the excavator via the network. When the excavator operator finishes digging the material, automated unloading is initiated. The robotic arm, bucket, and rotating chassis autonomously plan their movement trajectory to automatically unload the material to the designated coordinate position. When the transport vehicle detects a full load signal, it sends a full load message to the cloud, which instructs the excavator to stop loading the material. At this point, the excavator operator stops loading the material for the vehicle.

[0048] The process of transport vehicles arriving at the excavator's working area Figure 2 See the flowchart for the automated unloading process of the excavator. Figure 3 .

[0049] The motion planning of an excavator robotic arm mainly includes forward kinematics calculation and inverse kinematics calculation. Forward kinematics calculation controls the rotation angles and speeds of each joint of the excavator robotic arm, i.e., the spatial coordinates of the excavator robotic arm joint variables and the pose information of the corresponding end effector bucket. Given the excavator robotic arm parameters and the target angle of each joint, the position and orientation of the end effector bucket are solved. Inverse kinematics calculation, on the other hand, knows the position and orientation of the excavator bucket and inversely deduces the position and orientation of each joint of the excavator robotic arm based on the excavator robotic arm parameters. This invention obtains the coordinates of the midpoint of the cargo box of the transport vehicle provided by the cloud. These coordinates are the final bucket position calculated by inverse kinematics. From this position and the relevant parameters of the excavator robotic arm, the pose of the robotic arm joints is deduced.

[0050] An excavator's robotic arm generally consists of four parts: a rotating chassis that connects to the motion system, the boom, the arm, and the bucket. It also has sensors for measuring the joint motion angles and a power supply device.

[0051] The cloud sends the coordinates of the center point of the cargo box of the transport vehicle to the excavator. After the excavator operator fills the bucket with material, he starts the automated unloading. The excavator will record the position and posture of the robotic arm when the automated unloading is started. At the same time, it processes the coordinates of the center point of the cargo box from the cloud. Based on the initial target and the target of the center point of the cargo box, the robotic arm reaches the center point of the cargo box through the planned path and unloads the material in the bucket. Then it goes to the loading point through the planned path, and the operator performs the next material excavation.

[0052] See Figure 4 Considering the characteristics of excavator robotic arms, the system can be simplified into a three-degree-of-freedom system:

[0053] Where θ1 is the base rotation angle, θ2 is the boom movement angle, θ3 is the boom curvature angle (fixed), θ4 is the forearm movement angle, and φ is the bucket movement angle. a1, a2, and a3 are all parameters of the excavator's robotic arm length, and the oxyz coordinate system is the base coordinate system of the working device. θ1, θ2, and θ4 are obtained through inverse calculation based on the midpoint coordinates of the cargo box from the cloud, with θ3 being a fixed angle. φ is the bucket unloading angle; the angle is moved to its maximum when the target angle is reached, at which point all the material in the bucket will be unloaded into the cargo box of the transport vehicle.

[0054] The excavator's robotic arm pose is obtained by inverse kinematics calculation based on the coordinates of the midpoint of the cargo box. This invention uses a geometric method for solution, and the process is as follows:

[0055] Calculate angle θ1 based on the simplified three-degree-of-freedom system. Assume the center coordinates of the loading point are at point A, and establish a coordinate system with the excavator as the origin.

[0056] θ1 is the angle of rotation required for the excavator bucket to move to loading point A, X is the distance from the loading point to the excavator, provided by inertial navigation positioning data, and Y is the excavator hardware parameter, i.e., the length of the robotic arm. θ1 is calculated as follows:

[0057]

[0058] 2) The motion angles of each joint of the robotic arm are calculated as follows:

[0059] L1 is the boom length; L2 is the forearm length; L3 is the distance from the bucket center to the forearm connection point, which is a hardware constant. Point A is the known midpoint of the cargo box of the transport vehicle. γ is the angle between L3 and the x-axis. From this point, the motion angles θ2, θ4, and φ are deduced. Let the coordinates of point A be (x, y). The solution process is as follows:

[0060] C x = x - L3 × Cos(γ)

[0061] C y = y - L3 × Sin(γ)

[0062]

[0063] Similarly, we can obtain the value of Cos(α) and then calculate θ2:

[0064]

[0065] Therefore, the value of the cosine of θ4 is:

[0066]

[0067] Therefore, the value of φ is:

[0068] φ=γ-θ2-θ4

[0069] After calculating θ2, θ4, and φ, the excavator's robotic arm can move to automatically unload the material from the excavation area into the cargo box of the transport vehicle.

[0070] When adjusting the robotic arm, take into account the height of the cargo box of the transport vehicle. Raising the robotic arm at an angle greater than the cargo box angle will prevent the excavator robotic arm from touching the cargo box of the transport vehicle.

[0071] Excavator booms are highly flexible. However, due to the complex working environment of excavators, blind spots may exist in the operator's field of vision in certain situations. Combined booms offer flexibility, and using automated unloading not only reduces the difficulty of operation for the operator but also avoids operational errors caused by blind spots. Generally, automated unloading requires the boom, stick, and bucket to move in coordinated motion simultaneously, reducing the possibility of operational errors and lessening the operator's workload.

[0072] After the automated unloading is completed, the robotic arm readjusts to the loading area according to the movement path, waiting for the driver's next operation.

[0073] To verify the above facts, a Matlab simulation experiment was conducted, and the code implementation is as follows: Figure 8 :

[0074] The Matlab simulation results are as follows: Figure 9 .

[0075] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for automating excavator operations, using an excavator system, the excavator system comprising: The excavator body is equipped with an onboard inertial navigation system and an automated unloading control system, and also includes a cloud data processing system. The onboard inertial navigation system and the automated unloading control system are communicatively connected to the cloud data processing system. The onboard inertial navigation system collects the current coordinate information of the excavator body and sends it to the cloud data processing system. The cloud data processing system processes the data using a preset automated operation algorithm and feeds back control signals to the automated unloading control system. The automated unloading control system controls the excavator body to execute the control signals to achieve automated unloading operations. The system is characterized by the following steps: Step S1: The cloud data processing system receives the real-time location of the excavator sent by the vehicle-mounted inertial navigation system and guides the driver to the material loading point to excavate materials; Step S2: The excavator body determines whether the excavator is fully loaded. If it is fully loaded, the cloud data processing system sends a stop automatic loading operation command to the automatic unloading control system; automatic loading ends. If it is not fully loaded, the cloud data processing system sends a start automatic loading operation command and an operation movement path command planned according to the preset automatic operation algorithm to the automatic unloading control system, and controls the excavator body to complete the unloading operation at the cargo box position. Step S3: The cloud data processing system sends the planned path to the automated unloading control system. After the excavator body arrives at the loading point, the driver performs the next material excavation. The automated loading operation instructions include forward kinematics calculation and inverse kinematics calculation. The forward kinematics calculation controls the rotation angle and speed of each joint of the excavator's robotic arm, that is, the spatial coordinates of the excavator's robotic arm joint variables and the pose information of the corresponding connected end-cap bucket. Given the excavator's robotic arm parameters and the target angle of each joint, the position and orientation of the end-cap bucket are solved. The inverse kinematics calculation, knowing the position and orientation of the excavator bucket, reversely deduces the position and orientation of each joint of the excavator's robotic arm based on the excavator's robotic arm parameters. Inverse kinematics solution includes the following steps: Step 1) Calculate the angle based on the simplified three-degree-of-freedom system. Assume the center coordinates of the loading point are at point A, and establish a coordinate system with the excavator as the origin. θ1 is the angle that the excavator bucket needs to rotate to reach the loading point A. X is the distance from the loading point to the excavator, provided by inertial navigation positioning data. Y is the excavator hardware parameter, i.e., the length of the robotic arm. θ1 is calculated as follows: ； Step 2) Calculate the motion angles of each joint of the robotic arm; let L1 be the length of the upper arm; L2 be the length of the lower arm; L3 be the distance from the center of the bucket to the connection point of the lower arm (a hardware constant); point A is the known midpoint of the cargo box of the transport vehicle; γ is the angle between L3 and the x-axis. From this point, deduce the motion angles θ2, θ4, and φ; let the coordinates of point A be (x, y), then: ； Similarly, we can obtain the value of cos(α) and then calculate θ2: ； Therefore, the value of the cosine of θ4 is: ； Therefore, the value of φ is: ； After calculating θ2, θ4, and φ, the excavator's robotic arm can move to automatically unload materials from the excavation area into the cargo box of the transport vehicle.

2. The method for automating excavator operation according to claim 1, characterized in that, The forward kinematics solution includes the following steps: Step 3) Construct a mathematical model. Based on the characteristics of the excavator's robotic arm, simplify the system into a three-degree-of-freedom system. Let θ1 be the base rotation angle, θ2 be the boom movement angle, θ3 be the boom curvature angle (fixed), θ4 be the forearm movement angle, φ be the bucket movement angle, and a1, a2, and a3 be the excavator robotic arm length parameters. Establish the oxyz coordinate system as the base coordinate system of the working device. Step 4) Based on the coordinates of the midpoint of the cargo box in the cloud, θ1, θ2, and θ4 are obtained through inverse calculation. Among them, θ3 is a fixed angle, and φ is the bucket unloading angle. When the target angle is reached, the angle is moved to the maximum. At this time, all the material in the bucket will be unloaded into the cargo box of the transport vehicle.

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