WORK MACHINE AND METHOD FOR AUTOMATIC CONTROL OF THE TRAJECTORY OF A WORK DEVICE WITH RESPECT TO TARGET AREA PLANNING

Abstract

A method for controlling the movement of a ground-engaging tool for a working machine, such as a bucket or blade coupled to the machine frame via a boom assembly, and in particular a point of interest, such as a tool tip, is described. A number of previous and / or future positions for a point of interest associated with the ground-engaging tool are determined based on acquired data about the point of interest, including its current position, trajectory, and velocity. A convergence trajectory is calculated for the point of interest from its current position and with respect to a target surface profile, at least partially based on the determined previous and / or future positions along the current trajectory.Output signals are generated, at least in part, based on the calculated convergence trajectory, for the automatic control of the movement of the point of interest.

Description

AREA OF REVELATION

[0001] The present disclosure relates generally to working machines, such as construction and forestry machines with ground-intervention tools, and in particular to systems and methods for managing the trajectory of an area of ​​interest on a machine tool in order to maintain a target surface leveling. BACKGROUND

[0002] Examples of such working machines include excavators, motor graders, backhoe loaders, front-end loaders, and others. These machines typically have ground-penetrating units with tracks that support the undercarriage on the ground surface; however, working machines within the scope of this disclosure may also include stationary frames with one or more movable components. These working machines may further include a working device comprising one or more components used to modify the terrain based on control signals from and / or in conjunction with a movement of the working machine.

[0003] Control systems are often integrated into machine platforms to manage the movement of the work tool in order to perform automation tasks. Particularly in grading control systems, the machine control system must perform calculations to manage the trajectory of a point of interest on the machine work tool in order to maintain the desired surface leveling. SUMMARY

[0004] The present disclosure provides an improvement over conventional systems, at least in part by introducing a novel working machine, a novel control system and a method for using time-related preview and look-back data points with respect to a current trajectory of the point of interest to plan the forthcoming trajectory path.

[0005] In a particular and exemplary embodiment, a computer-implemented method for controlling the movement of a ground-penetrating tool for a working machine is provided, wherein the ground-penetrating tool is located at a first end of a working device comprising one or more components and is coupled at a second end to a main frame of the working machine and is independently movable with respect to this. The method comprises: determining one or more future positions for a point of interest in relation to the ground-penetrating tool based on acquired data about the point of interest, including its current position, trajectory, and velocity; and calculating a convergence trajectory for the point of interest from its current position and with respect to a target surface profile, at least partially based on the current position and velocity.the determined one or more future positions along the current trajectory; and generating output signals for automatic control of the movement of the point of interest, at least in part, based on the calculated convergence trajectory.

[0006] In one exemplary aspect of the above-mentioned method implementation, one or more properties of the calculated trajectory can be adjusted based on one or more predicted gradient changes associated with several specific future positions. These one or more properties can, for example, include the extent of the trajectory.

[0007] In another exemplary aspect according to the above-mentioned method implementation form, one or more changes in gradient can be predicted using calculated surface normal vectors, each in connection with several specific future positions.

[0008] In another exemplary aspect according to the above-mentioned method implementation form, one or more previous positions of the point of interest can be determined and the convergence trajectory can furthermore be calculated at least partially based on the determined one or more previous positions.

[0009] In another exemplary aspect according to the above-mentioned method implementation form, one or more properties (e.g. extent) of the calculated convergence trajectory can be adjusted based on one or more predicted gradient changes in connection with several specific previous and future positions.

[0010] In another exemplary aspect according to the above-mentioned method implementation form, one or more changes in gradient can be predicted using calculated surface normal vectors, each in connection with several specific previous and future positions.

[0011] In another exemplary aspect according to the above-mentioned method implementation form, the method can include mapping a current surface profile and the target surface profile in a three-dimensional coordinate frame and calculating an error between the current surface profile and the target surface profile with respect to a section previously traversed by the point of interest.

[0012] In yet another exemplary aspect according to the above described method implementation form, feedback, which includes the calculated error, can be generated for further calculation of the convergence trajectory and / or control of the movement of the point of interest.

[0013] In a further embodiment, a working machine disclosed herein may comprise a ground-engaging tool at a first end of a working device, which includes one or more components and is coupled at a second end to a main frame of the working machine and is independently movable with respect to this. One or more processors, which, for example, include a machine control or are otherwise integrated therewith, may be configured to instruct the execution of steps according to the above-mentioned embodiment of the method and optional aspects thereof.

[0014] For the person skilled in the art, upon reading the following disclosure in conjunction with the accompanying drawings, numerous tasks, features and advantages of the embodiments presented here will be readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a side view showing an excavator as an exemplary self-propelled work machine according to an embodiment of the present disclosure. Fig. Figure 2 is a block diagram illustrating an exemplary control system according to an embodiment of the present disclosure. Fig. Figure 3 is a flowchart illustrating an exemplary embodiment of a method for controlling a point of interest to a target trajectory, as disclosed herein. Fig. Figure 4 is a flowchart illustrating an exemplary embodiment of a method for determining a target trajectory as disclosed herein. Fig. Figure 5 is a graphical representation that provides an example of trajectory updates resulting from changes in ground surface profile. Fig. Figure 6 is a graphical representation that provides an example of trajectory updates resulting from error variance. Fig. Figure 7 is a graphical representation that illustrates an example of trajectory updates resulting from user-initiated speed adjustments. Fig. Figure 8 is a graphical representation that provides an example of trajectory updates resulting from preview and / or lookback points with respect to a current position of the point of interest, according to an embodiment of a system and a method as disclosed herein. Fig. Figure 9 is a graphical representation that provides an example of trajectory updates which further take into account variance in surface normal vectors from different preview points, according to an embodiment of a system and a method as disclosed herein. Fig. Figure 10 is a graphical representation that provides an example of trajectory updates which further take into account variance in surface normal vectors of backview and preview points, according to an embodiment of a system and a method as disclosed herein. DETAILED DESCRIPTION

[0015] With reference to the following Fig. Sections 1-10 now describe various embodiments of a system and a method for controlling the trajectory and speed of an area of ​​interest of a working tool attached to the working device of a working machine, for example to precisely control the movement of the working tool over change points during a target surface leveling.

[0016] Fig. Figure 1 represents an exemplary self-propelled work machine 120, for example in the form of an excavator with tracks. The work machine 120 comprises an undercarriage 122, which includes a first and a second ground engagement unit 124 (e.g., tracks). In Fig. Figure 1 shows only one of the ground engagement units. The other ground engagement unit is parallel to the one shown. The undercarriage includes a first and a second drive motor (not shown) for driving the first and second ground engagement units, respectively. The ground engagement units can be driven at the same speed to move the undercarriage forward (e.g., in a forward direction indicated by arrow 126) or backward (e.g., in a direction opposite to arrow 126) with respect to the terrain 128 below (e.g., the ground or other material on which the undercarriage is supported). The ground engagement units can also be driven at different speeds to allow the undercarriage to turn relative to the terrain at an angle to the forward direction indicated by arrow 126.

[0017] A main frame 130 is supported by the undercarriage 122 by a pivot bearing 132, so that the main frame can pivot about a main frame pivot axis 134 with respect to the undercarriage. The pivot axis is substantially vertical if the underlying ground 128, with which the ground engagement units 124 engage, is substantially horizontal. (For the purposes of this discussion, "horizontal" and "vertical" refer to a plane defined by the ground engagement units.) A pivot motor (not shown) is configured to pivot the main frame on the pivot bearing about the pivot axis with respect to the undercarriage.

[0018] In the illustrated embodiment, where the working machine 120 is an excavator, a working attachment 140 extends from the main frame 130. Fig. 1 The work equipment is configured as a boom assembly. The work equipment comprises conventional components in the form of a boom 142, an arm 144, and a work tool 146. The work tool includes a point of interest (POI) 148 that engages with sections of terrain (or other materials) to be moved or removed.

[0019] The boom 142 is pivotally connected to the main frame via a boom-frame joint 150, which provides a horizontal pivot axis for the boom. The arm is pivotally connected to the boom via an arm-boom joint 152. In the illustrated embodiment, the working tool 146 is an excavator bucket, which is pivotally connected to the arm 144 via a working tool-arm joint 154, which is positioned near a free end of the arm. In the illustrated embodiment, a first end of a deflection lever connector 160 is pivotally connected to the arm via a deflection lever-arm joint 162, which is positioned offset from the free end of the arm. A second end of the deflection lever connector is pivotally connected to a tool connector 164. In the context of the illustrated (excavator) machine 120, the tool connector is a bucket connector.

[0020] A boom actuator 170 causes the boom 142 to pivot relative to the main frame 130. The boom actuator can be a hydraulic motor. In the illustrated embodiment, the boom actuator is a hydraulic piston-cylinder unit to which pressurized hydraulic fluid is selectively supplied to move the piston in the cylinder, extending or retracting it. The pressurized hydraulic fluid is supplied by a hydraulic system (not shown) and is controlled by manual controls, automatic controls, or a combination of manual and automatic controls. Similarly, an arm actuator 172 causes the arm 144 to pivot relative to the boom.A working tool actuator 174, which acts on the working tool via the deflection lever connector 160, the deflection lever arm connecting joint 162 and the tool connecting piece 164, causes the working tool (the shovel) 146 to pivot relative to the arm.

[0021] The working device 140 extends along a working direction (represented by arrow 176) of the working device from the main frame 130. Fig. 1. The working direction refers to the main frame. Although the working direction, according to the illustration, runs parallel to the forward direction (arrow 126) of the undercarriage 122, it can run at an angle to the forward direction depending on the rotational position of the main frame relative to the undercarriage. The working direction can also be described as a working direction of the boom 142.

[0022] As described here, the control of the working device 140 refers to controlling the positioning of one or more of the associated components (e.g., the boom 142, the arm 144, and the working tool 146) to control the movement of the point of interest 148 of the working tool in relation to material to be manipulated (e.g., the material to be moved or removed).

[0023] The actuators 170, 172, and 174 of the work device 140 can be selectively actuated to pivot the boom 142 about the respective boom-frame joint 150, to pivot the arm 144 about the arm-boom joint 152, and / or to pivot the working tool 146 about the working tool-arm joint 154. By coordinating the movements of the boom, arm, and working tool of the work device, the point of interest on the working tool engages with and acts upon the material to be manipulated along a selected trajectory and at a target velocity. The selected trajectory can be curved, as shown (e.g., by pivoting the working tool about the working tool-arm joint or by pivoting the arm about the arm-boom joint).The selected trajectory can also be linear, by coordinating the swiveling of the boom, arm and working tool using methods of inverse kinematics or other suitable methods (e.g., non-feedback modeling) to determine the respective swiveling velocities of the three components of the working device 140.

[0024] In the illustrated embodiment, an operator cabin 192 is positioned on the main frame 130. In this embodiment, both the operator cabin and the working device 140 are attached to the main frame such that the operator cabin points in the working direction (arrow 176) of the working device. In this embodiment, a control panel 194 is positioned in the operator cabin.

[0025] The main frame 130 also supports a motor 196 for operating the working machine 120. The motor can be a diesel internal combustion engine or another power source. In the illustrated embodiment, the motor drives at least one hydraulic pump (not shown) to supply hydraulic power to the various operating systems of the working machine.

[0026] In the illustrated embodiment, a sensor system 204 is also included (see Fig. 2) attached to the working machine 120. As in Fig. As shown in Figure 1, the sensor system comprises a first sensor 204a attached to the main frame 130, a second sensor 204b attached to the boom 142, a third sensor 204c attached to the arm 144, a fourth sensor 204d attached to the deflection lever connector 160, and a fifth sensor 204e attached to the working tool 146.

[0027] In the illustrated embodiment, all of the first through fifth sensors are inertial measurement units (IMUs). IMUs are tools that acquire a variety of motion-based and position-based measurements, including, but not limited to, velocity, acceleration, angular velocity, and angular acceleration. IMUs contain a number of sensors, including, but not limited to, accelerometers, which measure (among other things) velocity and acceleration; gyroscopes, which measure (among other things) angular velocity and angular acceleration; and magnetometers, which measure (among other things) the strength and direction of a magnetic field.

[0028] In general, as discussed above, an accelerometer provides measurements of (among other things) the force caused by gravity, while a gyroscope provides measurements of (among other things) the motion of a rigid body. The magnetometer provides measurements of the strength and direction of the magnetic field (among other things) with respect to known internal constants or with respect to a known, accurately measured magnetic field. The magnetometer provides measurements of a magnetic field to obtain information about the positional or angular orientation of the IMU; similarly, the gyroscope also provides information about the positional or angular orientation of the IMU. Accordingly, the magnetometer can be used instead of the gyroscope, or in combination with the gyroscope and in addition to the accelerometer, to obtain local information and coordinates about the position, motion, and orientation of the IMU.

[0029] An accelerometer is an electromechanical device or tool used to measure acceleration (e.g., in meters per second squared (m / s²)). 2Accelerometers are designed to measure acceleration, which is defined as the rate of change of velocity (e.g., in meters per second (m / s)) of an object. They detect either static forces (e.g., gravity) or dynamic acceleration forces (e.g., vibration and motion). An accelerometer can incorporate sensing elements that measure the force due to gravity. By measuring the magnitude of the static acceleration due to Earth's gravity, an accelerometer can provide data on the angle at which the object is tilted relative to the Earth, an angle that can be determined within an XYZ-axis coordinate system. However, if the object is accelerating in a particular direction, such that the acceleration is dynamic (rather than static), the accelerometer will produce data that does not effectively distinguish the dynamic forces of motion from the force due to Earth's gravity.A gyroscope is a device used to detect changes in orientation based on angular velocity (rad / s) or angular acceleration (rad / s). 2 ) of the object. A gyroscope can be a mechanical gyroscope, a gyroscope with a micro-electro-mechanical system (MEMS), a ring laser gyroscope, a fiber optic gyroscope, and / or other gyroscopes according to the state of the art. In principle, a gyroscope is used to measure changes in the angular position of a moving object, whereby the angular position of the object can be determined within an XYZ axis coordinate frame.

[0030] In one embodiment, for each of at least one connecting joint assigned to a working device 140 (e.g., each coupled set of components in a boom arrangement), detection elements from the received working device position sensor output signals can be fused in an independent coordinate frame that is at least partially assigned to the respective connecting joint, wherein the respective independent coordinate frame is independent of a global navigation frame for the working machine 120, wherein, for example, measurements received by working device position sensors 204 can be aggregated to provide a target output power of the working device of the working machine.

[0031] As in Fig. As shown schematically in Figure 2, the self-propelled work machine 120 includes a control system comprising a controller 210. The controller can be part of the work machine's machine control system or it can be a separate control module. The controller is optionally mounted in the operator's cab 192 on the control panel 194. The machine control can include a user interface 212, such as a control panel. The user interface can include a user interface tool 214, such as an input / output device (e.g., a keyboard, a joystick, or the like). The user interface can also include a display 216.

[0032] The machine control 210 is configured to receive input signals from some or all of the various work tool position sensors 204a...204e that together define the sensor system 204 or are otherwise part of it. The sensors of the sensor system can generally be discrete, but signals representing more than one input parameter can be provided by the same sensor.

[0033] Although this in Fig. Unless explicitly shown in Figure 2, the sensor system 204 may also refer to signals provided by the machine control system. For example, in one embodiment, machine location sensors may include a global navigation satellite system (GNSS) receiver.

[0034] Machine location determination sensors can additionally or alternatively include, for example, ground speed sensors, steering sensors or the like, or equivalent inputs from the machine control system.

[0035] Alternative work tool position sensors may include, for example, rotary encoders attached to pivot pins to detect the relative rotational positions of the respective components, displacement encoders attached to hydraulic cylinders to detect their respective extension, or the like.

[0036] Additional sensors may be provided and configured to generate speed measurement signals that represent a speed measurement of respective actuators, including, for example, hydraulic piston-cylinder units, which are assigned to the respective components of a working device (e.g., a boom assembly).

[0037] The controller 210 can be configured to generate outputs to the user interface 212 to display information for the operator. Additionally or alternatively, the machine controller can be configured to generate control signals for controlling the operation of individual actuators or to generate signals for indirect control via intermediate control units assigned to a machine steering control system 226, a machine tool control system 228, and an engine speed (drive) control system 230. The machine controller can generate control signals for controlling the operation of various actuators, such as hydraulic motors or hydraulic piston-cylinder units of the boom actuator 170, the arm actuator 172, and the work tool actuator 174.The control signals from the controller can be received by electro-hydraulic control valves assigned to the actuators, so that the electro-hydraulic control valves control the flow of hydraulic fluid to and from the respective hydraulic actuators in such a way as to control their actuation in response to the control signal from the controller.

[0038] The controller 210 can include or be associated with a processor 250, a computer-readable medium 252, a communication unit 254, a data storage device 256, such as a database network, and the above-mentioned user interface (control panel) 212 with the display 216 and the user interface tool (e.g., the input / output device) 214, with which an operator can enter instructions to the controller.

[0039] The control system described here can be a single controller possessing all the described functionality, or it can comprise multiple controllers in which the described functionality is distributed across the multiple controllers. The data storage can generally include hardware, such as volatile or non-volatile storage devices, drives, memory, or other storage media, as well as one or more databases located on it.

[0040] In Fig. Not specifically shown in Figure 2, the control unit 210 of the working machine 120 can, in some embodiments, furthermore receive inputs from remote devices assigned to a user via a respective user interface, for example, a display unit with a touchscreen interface, and generate outputs to these devices. Data transmission between, for example, a vehicle control system and a remote user interface can take the form of a wireless communication system and associated components that are generally known in the prior art. In certain embodiments, a remote user interface and vehicle control systems for the respective working machines can be further coordinated or otherwise interact with a remote server or other computing device for carrying out certain operations in a system as disclosed herein.

[0041] Various “computer-implemented” operations, steps, or algorithms, as described in connection with the controller 210 or with alternative but equivalent computing devices or systems, can be embodied directly in hardware, in a computer program product, such as a software module executed by the processor 250, or in a combination of both. The computer program product can reside in RAM, flash memory, ROM, EPROM, EEPROM, registers, on a hard disk, a removable disk, or in any other form of computer-readable medium 252 known in the art. An exemplary computer-readable medium 252 can be coupled to the processor 250 so that the processor 250 can read information from and write information to the memory / storage medium 252.Alternatively, the computer-readable medium 252 can be integrated into the processor 250. The processor 250 and the computer-readable medium 252 can be located in an application-specific integrated circuit (ASIC). The ASIC can be located in a user terminal. Alternatively, the processor 250 and the medium 252 can be separate components in a user terminal.

[0042] The term "processor," as used here, can refer to at least general or specific processing devices and / or logic known to those skilled in the art, including, but not limited to, a microprocessor, a microcontroller, a state machine, and the like. A processor can also be implemented as a combination of computing devices (e.g., a combination of a digital signal processor (DSP) and a microprocessor), multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0043] The communication unit 254 can support or provide communication between the machine control 210 and external systems or devices and / or support or provide a communication interface to the internal components of the self-propelled work machine 120. The communication unit 254 can include wireless communication system components (e.g., via a cellular modem, Wi-Fi® systems, Bluetooth® systems, or the like) and / or one or more wired communication ports, such as USB ports.

[0044] With reference to the following Fig. 5-7 and further using an excavator as an example of the work machine 120 for illustrative purposes, a grading control system (e.g., the controller 210) on such a machine attempts to manage the movement of the work tool 140, and in particular the working tool 146, in such a way that a point of interest 148 (often the tool tip, but could be any point on the work tool) is kept on a target grade 510. This grade can be defined as a flat plane or could be a complex surface represented digitally as a set of geometric data. As the point of interest crosses the surface in three-dimensional space, the control system must make decisions to move it to and keep it on the target surface.

[0045] As in Fig. As shown in Figure 5, the trajectory for the point of interest 148 may need to be continuously assessed and updated by the control system to switch from a current trajectory 512 (which in the example shown has a downward slope corresponding to a first section of the target leveling 510) to a future trajectory 514 (which in the example shown has a shallow slope corresponding to a second section of the target leveling) to accommodate changes in surface geometry.

[0046] As in Fig. As shown in Figure 6, the trajectory for the point of interest 148 can also be, or alternatively must be, updated by the control system to execute a current trajectory 512 (in the example shown, directly down to a first section of the target plan 510) before adopting a future trajectory 514 (which in the example shown has a shallow gradient corresponding to the first section of the target plan) to account for error variance.Although the example shown includes a current trajectory that runs directly down to the surface, it is clear to a person skilled in the art that even in similar contexts where the trajectory is updated to account for error variance, the current trajectory vector may be inclined slightly with respect to the ground surface in order to move towards the target planing and eventually meet it at a future position corresponding to the future trajectory shown.

[0047] As in Fig. As shown in Figure 7, the trajectory for the point of interest 148 can also be updated by the control system, or alternatively, must be updated to reflect changes in speed requested manually by the operator.

[0048] In Fig. Figure 3 shows an exemplary procedure 300 for tracking the movement of connecting joints to maintain a target trajectory (corresponding, for example, to a current section of a target surface leveling) for the point of interest 148 of a work tool 146. In a first step 310, the procedure receives a target trajectory for moving the point of interest. For example, the target trajectory could be a predetermined target trajectory that is part of a general terrain design plan (e.g., excavation). In a second step 312, the procedure receives inputs from the IMUs 204a, 204b, 204c, 204d, and 204e described above and determines a current position of the point of interest.In a third step 314, the method uses inverse kinematics or other suitable methods to determine different angles and slew speeds of the components of the working tool 140 to achieve the target speed of the point of interest. In a fourth step 316, the method applies controlled hydraulic pressures to the actuators 170, 172, and 174 to move the boom 142, arm 144, and working tool 146 to achieve the determined angles and slew speeds. In the fourth step 316, the method receives feedback from the IMUs, which allows the method to adjust the hydraulic pressures as needed to maintain the desired trajectory.

[0049] In various embodiments, the controller 210 can be configured to determine a target velocity for the point of interest 148, or, when functionally connected to another processing unit for this point, based on a currently known position of the point of interest and based on a desired movement of the point of interest relative to the terrain to be manipulated. The target velocity can, for example, be provided as an input to a velocity determination subsystem that performs a modeling procedure, such as determination by inverse kinematics based on the target velocity, to determine a desired boom slewing velocity, a desired arm slewing velocity, and a desired bucket slewing velocity.

[0050] As described above, the machine 120 and the method 300 enable the point of interest 148 of the working tool 146 to move along a desired trajectory. In certain embodiments, due to the positions of the disclosed pivot axes associated with the connecting joints 150, 152, 154, the point of interest can only move in a plane perpendicular to the pivot axes and parallel to the working direction (arrow 176). In further embodiments within the scope of this disclosure, additional components, fixings, sensors, and / or the like may be provided, enabling a point of interest 148 of a working tool 146 to move in at least one additional degree of freedom.

[0051] In Fig. 4 now describes an embodiment of a method 400 for further controlling a trajectory and a speed of the working device 140, and in particular the point of interest 148, with respect to a target surface leveling, and in particular for improving the accuracy of the machine control by means of change points between different trajectories.

[0052] In a first step 410, at least target surface profile data and current data on the point of interest can be received, obtained, or otherwise determined. The current data of the point of interest can preferably include its position, trajectory, and velocity. Such current data of the point of interest can be determined using methods disclosed above or by any means known to a person skilled in the art.

[0053] In one embodiment, the target surface profile can be determined in a machine coordinate system. In further embodiments within the scope of protection of the present disclosure, a position of the machine and the target surface profile parameters can be determined in a target surface coordinate system. In both examples, the grading control system can reliably direct the control of a grading operation in accordance with the determined target surface profile, whereby, for example, a movement of the machine and / or one or more machine components is controlled or directed at least partially based on the determined target surface profile and furthermore with regard to monitored positions and / or movements of the machine.In some embodiments, where, for example, a position of the point of interest in the same three-dimensional reference coordinate plane as the target surface profile data is desired, the position of the point of interest can first be determined in a first reference coordinate plane, wherein, for example, the position is determined with respect to a position on or in connection with the main frame of the machine, and then, as required, transformed into a second reference coordinate with provided or otherwise available target surface profile data.

[0054] In a second step (412), "forecast" points and / or "backward" points are determined in relation to the current position of the point of interest. As in Fig. As shown in Figure 8, these data points can represent an elevation 524 with respect to the target surface 510 (i.e., the distance between the target surface leveling and the point of interest 148) and, in some embodiments, can further represent a surface normal (i.e., a vector representing the position of the surface at the location of interest). The preview and preview points can, for example, be time-related. In the embodiment shown, the working tool 146 and the point of interest 148 are shown with respect to a current position 516 (i.e., at time t = t0), while a future position of the working tool and the point of interest after a certain period (i.e., t = t1) at the current trajectory 512 is represented as a preview working tool position 518 and a preview position 522 of the point of interest, respectively.

[0055] In a third step 414, using a specification of the elevation 524 (e.g., a distance to the surface) of the point of interest 148 at the current position 516, as well as the time-related preview elevation, a trajectory determination can be made that allows the point of interest to converge on the target surface. Since this is a time-related preview, the distance 526 traveled for this convergence typically varies with the current velocity of the point of interest.

[0056] In a fourth step 416, changes in the target surface profile 410 can be identified or predicted using surface normal vectors from one or more of the preview and / or review points. In an embodiment described in Fig. As shown in Figure 9, multiple preview points 520 (corresponding to time t=t1) and 530 (corresponding to time t=t2) can be used for the working tool 146 and the point of interest 148, potentially allowing for greater accuracy in the trajectory selection process. The working tool at the first preview point 518 and the point of interest at the first preview point 522 are generated based on the current position 516 and the current trajectory of the working tool 146 and the point of interest 148, and also with respect to the first preview time (t = t1). The working tool at the second preview point 528 and the point of interest at the second preview point 532 are also generated based on the current position and trajectory of the working tool 146 and the point of interest 148, and also with respect to the second preview time (t = t2).In particular, preview points located further away from the current position of the point of interest 146 could allow the determination of gradient changes in the area, an important indicator of an impending change that the control system must cope with.

[0057] Using the surface normal vectors 534 from various preview points, or in the illustrated embodiment, a first surface normal vector 534a corresponding to the point of interest at a first preview point 522, and a second surface normal vector 534b corresponding to the point of interest at a second preview point 532, the system can compare gradients of upcoming points along the current trajectory 512. Varying gradients, indicated by the surface normal vectors, inform the machine control that a change is imminent.

[0058] In a fifth step 418, this information can be used to manage one or more trajectory properties, such as the extent of the trajectory for the area of ​​interest, thereby effectively slowing down the working tool when approaching a changeover and preferably supporting the assurance of accurate removal through the changeover.

[0059] As further in Fig. As shown in Figure 10, a similar logic can be applied to a lookback point 540 (corresponding to time t = t - 1), where the machine control can assess the slope of the surfaces that the working tool has already traversed at the lookback point 536. Using the surface normal vector 534o, data for the lookback point serve as an indication that the point of interest is leaving a changeover point.

[0060] Similar to the previous scenario, the variance in surface normal vectors 534o from the lookback point 540 with respect to the current position 516 of the point of interest 148 can provide evidence of the change in the slope of the surface. This information can be used to modify one or more properties (for example, the extent) of the work tool trajectory, thereby ensuring that the work tool moves away from a surface change in a controllable manner.

[0061] The trajectory extent determination based on surface normal vectors 534 can generally affect the overall speed of the working tool 146 and / or the point of interest 148 entering and leaving a change point. Since the preview and / or lookback points are time-related, this can also affect the distance of these points relative to the point of interest 148 at the current position 516. This improves the accuracy of the machine control through a change point due to the "convergence" effect that occurs when the distance between the preview and / or lookback points is reduced during control at the change point.

[0062] As used here, the expression "one or more of" when used with a list of elements means that various combinations of one or more of the elements can be used, and only one of each element in the list may be necessary. For example, "one or more of" element A, element B, and element C could include, among others, element A or element A and element B. This example could also include element A, element B, and element C, or element B and element C.

[0063] It is thus evident that the devices and methods of the present disclosure readily achieve the stated objectives and advantages, as well as those inherent within the disclosure. Although certain preferred embodiments of the disclosure have been illustrated and described for illustrative purposes, the person skilled in the art may make numerous modifications to the arrangement and construction of the parts and steps, such modifications falling within the scope and essence of the present disclosure as defined by the pending claims. Each disclosed feature or embodiment may be combined with one or more of the other disclosed features or embodiments.

Claims

[1] Computer-implemented method (300, 400) for controlling the movement of a soil engagement tool (146) for a working machine (120), wherein the soil engagement tool is located at a first end of a working device (140) comprising one or more components (142, 144) and is coupled at a second end thereto to a main frame (132) of the working machine and is independently movable in this respect; wherein the method comprises: Determining one or more future positions for a point of interest (148) in connection with the ground intervention tool based on acquired data on the point of interest, which include a current position, a current trajectory and a current velocity thereof (410, 412); Calculating a convergence trajectory for the point of interest from the current position and with respect to a target surface profile, at least partly based on the determined one or more future positions along the current trajectory (414); and Generating output signals for automatic control of the movement of the point of interest at least partly based on the calculated convergence trajectory (418). [2] Computer-implemented method according to claim 1, comprising adjusting one or more properties of the calculated trajectory based on one or more predicted gradient changes associated with several specific future positions (416). [3] Computer-implemented method according to claim 2, wherein one or more features comprise a measure of the trajectory. [4] Computer-implemented method according to claim 2 or 3, wherein the one or more gradient changes are predicted using calculated surface normal vectors in each case in connection with several specific future positions (416). [5] Computer-implemented method according to claim 1 or 2, further comprising determining one or more prior positions of the point of interest and calculating the convergence trajectory further, at least in part, based on the determined one or more prior positions. [6] Computer-implemented method according to claim 5, comprising adjusting one or more properties of the calculated convergence trajectory based on one or more predicted gradient changes associated with several specific prior and future positions (416). [7] Computer-implemented method according to claim 6, wherein one or more features comprise a measure of the trajectory. [8] Computer-implemented method according to claim 6 or 7, wherein the one or more gradient changes are predicted using calculated surface normal vectors in each case in relation to several specific prior and future positions. [9] Computer-implemented method according to any one of the preceding claims, comprising: Mapping a current surface profile and the target surface profile in a three-dimensional coordinate frame; and Calculating an error between the current surface profile and the target surface profile with respect to a section previously traversed by the point of interest. [10] Computer-implemented method according to claim 9, comprising generating feedback comprising the calculated error for further calculation of the convergence trajectory and / or control of the movement of the point of interest. [11] Working machine (120) comprising the following: a ground engagement tool (146) at a first end of a working device (140) comprising one or more components (142, 144) and coupled at a second end to a main frame (132) of the working machine and being independently movable in this respect; and one or more processors (210, 250) configured to instruct the execution of steps in a method according to any one of claims 1 to 10.

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