Patent Application
20160054739
Not applicable.
The disclosure relates to a method for controlling a tool pivotably mounted to an articulated boom connected to a work machine having a control unit. The disclosure relates to a system for controlling a tool pivotably mounted to an articulated boom connected to a work machine. The disclosure relates to a work machine, particularly a forest machine. The disclosure relates to a computer program and a computer software product.
Work machines, in particular forestry equipment and forest machines, e.g. harvesters and forwarders, have an articulated boom and a tool at the tip of the boom. The tool can be e.g. a harvester head, a felling head, a harvesting and processing head, or a log grapple. The tool can be used e.g. to cut standing trees, to process felled trees or to grab objects, such as logs or tree trunks. When using such a tool, it is moved under the control of an operator of the work machine to a desired position mainly by controlling the position of the boom and moving the tool with the boom, and optionally also by moving the work machine. Thereafter, or meanwhile, also the tool itself must be oriented according to the need. The tool is correctly oriented in relation to e.g. a standing tree to be harvested or a log lying on the ground or in a pile.
It has been noticed that turning the tool to a correct orientation takes some time and may be somewhat cumbersome for the operator. Thus, the work machine is not efficiently used and/or not convenient to use. Furthermore, repetitive positioning of the tool during long work periods can cause operator fatigue, which may lead to decreased productivity.
The solution to be presented is directed to overcoming one or more disadvantages noted above and associated with work machines having controllable tools.
According to the presented solution and the method, the direction a predetermined point of the boom or the tool is moving to, i.e. the moving direction, is determined, and the orientation of the tool, as a function of one or several predetermined dependencies, is controlled while the predetermined dependencies define at least the orientation of the tool in relation to the moving direction.
According to an example of the solution, the velocity of the predetermined point is determined together with the moving direction.
According to a further example of the solution, the predetermined point is the tip of the boom or the point of the boom the tool is connected to. For example, the tool may be a harvester head, a felling head, a harvesting and processing head, or a log grapple. For example, the work machine may belong to mobile forestry equipment and is a forest machine, for example a harvester or a forwarder. For example, the tool is adapted to handle logs, tree trunks or standing trees.
According to the presented solution, the system for controlling a tool pivotably mounted to an articulated boom connected to a work machine comprises a control unit adapted to automatically determine the direction a predetermined point of the boom or the tool is moving to, i.e. the moving direction, to control the orientation of the tool as a function of one or more predetermined dependencies, the predetermined dependencies defining at least the orientation of the tool in relation to the moving direction, and to generate control signals for controlling one or more actuators orienting the tool according to the one or more predetermined dependencies.
According to an example of the solution, the system has one or more sensors located in the boom or at the tool and operably connected to the control unit. The control unit is adapted to receive information or data indicative of the moving direction of the predetermined point or the orientation of the tool, or both, from the one or more sensors.
According to an example of the solution, the computer software product comprises a computer-readable medium and program code means stored in the computer-readable medium, wherein the computer software product is arranged to execute the steps of the method according to the presented solution, when said computer program is run in a control computer. According to an example, the control computer is the control unit of a forest machine. In the presented solution, for orienting of the tool, determining a target location for performing work with the tool can easily be made by an operator of the work machine. When the operator starts to move the boom towards the target location, e.g. a standing tree to be felled or a location for grapping, loading or unloading a log or a tree trunk. In this way, the moving direction of the predetermined point provides information on the relative position between the current location of the tool and the target location when the tool is being mounted at the predetermined point mentioned above. In this way, the tool can be oriented by using information on the moving direction of the predetermined point, e.g. the tip of the boom. The tool can be oriented e.g. with respect to the work machine to an orientation optimized for performing tasks.
The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features and advantages will become apparent from the description, the drawings, and the claims.
Reference will now be made to the examples which are illustrated in the accompanying drawings. Wherever possible, the same or corresponding reference numbers will be used throughout the drawings to refer to the same or corresponding parts or features.
a, 1b show examples of work machines having a boom and a tool,
a shows a work machine having a tool, wherein the tool opens to an opening direction and a working location is located in another direction,
b shows the work machine of
a, 3b show a work machine having a tool arranged at the tip of a boom; and the moving direction of the tip of the boom, which moving direction points towards a working location,
a-4d show a work machine having a tool arranged at the tip of a boom and the moving direction of the tip of the boom during loading and unloading.
a shows an example work machine 10 in which the presented solution can be applied. The work machine may be a forest machine, for example a harvester.
b shows another example work machine 10 in which the presented solution can be applied. The work machine may a forest machine, for example a forwarder.
The work machine 10 comprises a frame 12, a cabin 14 with an operator's station, an engine 15 as the source of power and an articulated boom 20 on the frame 12. The frame 12 may be articulated and have two or more frame sections 12a, 12b connected one after the other by means of a controlled joint. The frame 12 is wheeled and supported by several wheels. Alternatively, the frame 12 may have an endless track arrangement for supporting the frame 12 and to drive the work machine 10. The work machine 10, as shown in
The boom 20 is mounted onto a slewing apparatus 22 connected to the frame 12. By turning the slewing apparatus 22, the boom 20 can be rotated about an axis N that is parallel to the surface normal of the plane on which the work machine 10 stands or moves. The axis N is oriented vertically or substantially vertically. In an example of the solution, the boom 20 with the slewing apparatus 22 may further be mounted on a tilting apparatus connected to the frame for tilting the boom 20 such that the axis N is controllably tilted.
The boom 20 may have two or more boom sections connected one after the other. Two or more boom sections are connected to each other by means of joint arrangements controlled by means of one or several actuators, e.g. a cylinder actuator.
In the examples of
One or more boom sections of the boom 20 may operate telescopically. The extension and the length of the telescopically operating boom section is controlled by means of two or more boom section parts arranged movably within each other. One or several actuators, e.g. cylinder actuators, may be used to control the relative positions of the boom section parts. The cylinder actuator is connected to the boom section with boom section parts and the cylinder is located either inside or outside the boom section. A tool may be connected to the tip of the boom section part representing the tip of the boom 20.
According to an example and
In the presented solution, the tool 30 is connected to the boom 20. Preferably, the tool is connected at the end of the boom 20 or the first boom section 24 and represented by the tip P of the boom 20. The tool 30 is rotatably connected to the tip P of the boom 20 by means of an actuator 32, e.g. a rotator. With the actuator 32, the tool 30 suspended to the actuator 32 can be controllably rotated about a rotation axis X that is typically oriented vertically or substantially vertically. The orientation of the tool 30 is thus controlled with the actuator 32.
According to an example and
The tool 30 may be a harvester head, a felling head, a harvesting and processing head, a harvester head suitable to be used as a log grapple, or a log grapple. The tool 30, grabbing a standing tree from a side, needs to be oriented e.g. towards the tree standing vertically. A predetermined side of the tool 30 faces the standing tree. According to an example and
The tool 30 may have two or more arms pivotally connected to a housing of the tool 30 for grabbing a tree, a log or a tree trunk e.g. from two opposite sides. A mechanism driven by an actuator, e.g. a motor or a cylinder actuator, is connected to the housing for moving the arms to an open position and a closed position. In a harvester head, the arms may be additionally constructed as delimbing blades.
The tool 30 may further have tilting devices for changing the orientation of the tool 30 or the arms from a horizontal direction to a vertical direction and vice versa. Thus, a harvester head can grab logs or tree trunks lying horizontally and a log grapple can grab logs or tree trunks standing vertically.
One or more boom sections of the boom 20 operate by raising and lowering a tool or another boom section connected to the boom section. The raising and lowering takes place on a vertical or substantially vertical plane. According to an example and
One or more control joysticks, or other control devices, at the operator's station may be used by an operator to move the boom 20, the tip P of the boom or the tool 30 towards a target location. The joysticks and control devices may be operably connected with a control unit 50 of the work machine 10 and located e.g. in the cabin 14 or on the frame 12. A display may be connected to the control unit 50 for showing information and data to the operator. The control unit 50 is operably connected with various actuators associated with the boom 20 and other components of the work machine 10. Control signals from the joysticks and the control devices are communicated to the control unit 50, and the control unit 50 is operable to responsively control the various actuators to rotate the boom 20, move and change the position of the boom 20 and the tool 30, rotate the tool 30 and operate the tool 30 for performing work or grabbing with the arms of the tools 30.
The control unit 50 may a programmable microprocessor-based device with a memory device and associated computer program code, for generating control signals to responsively control the various actuators. The computer program code may be in a form of a control program or a control algorithm, or appropriate computer software, running or being executed under the control of a control computer, i.e. the control unit. The associated computer program code may be embodied on a computer readable medium. The control unit 50 may have a distributed configuration with several subunits communicating with each other's. In the context of this description, the term “automatic” refers to control methods performed by the control unit 50 based on the input information received by the control unit, e.g. from sensors. The control unit utilizes the generated control signals to automatically implement the control methods.
The actuators may be motors or cylinder actuators utilizing hydraulic energy and pressurized medium which is transmitted to the actuator by means of e.g. lines and flexible hoses. An apparatus needed for generating the hydraulic energy is placed in e.g. the frame 12 or is operatively connected to the engine 15. Hydraulic energy is distributed e.g. in the form of pressurized medium to the actuators via a control circuit presenting necessary valves and components for controlling the flow of the pressurized medium. Some actuators may utilize electric energy stored in an accumulator or generated with a generator operatively connected to the engine 15. The control circuit is controlled based on control signals from the control unit under the control of the operator or the automatic control of the control unit.
An embodiment of the presented solution will now be discussed with reference to
a shows a work machine 10 having a tool 30 pivotably mounted to a tip P of a boom 24 via an actuator 32. The work machine 10 with the tool 30 may be a forest machine according to the examples explained above or the harvester referred to above in the context of
The tool 30 may have a predetermined opening direction Ō defining e.g. a direction from which the tool 30 can receive an object, e.g. the tree 65. Throughout this description, overlining “
The tool 30 may have a predetermined holding direction
When the tool 30 is holding a longitudinal object, or several longitudinal objects, the holding direction
According to an example of the presented solution, the orienting of the tool 30 takes places automatically while the operator takes care of controlling the boom 20 to move a predetermined point of the boom 20, the tool 30 or the tip P of the boom 20 to a direction chosen by the operator, i.e. the moving direction
The tool 30 is automatically controlled according to a predetermined dependence defining the orientation of the tool 30 in relation to the moving direction
The examples 1), 2) and 4) apply at least to the examples of
Furthermore, before applying the examples listed above, the tool 30 may have been controlled to an initial orientation in which e.g. the opening direction Ō or the holding direction
a shows an example case for the location of the target location 60 in relation to the work machine 10. The target location 60 is represented by the standing tree 65. The tool 30 is intended to grab the tree 65. When the operator of the work machine 10 notices the target location 60, he/she starts to move the tool 30 with the boom 24 towards the target location 60. As the boom 24 moves, the tip P of the boom 24 has a velocity
a and 3b show two other example cases for the location of the target location 60 in relation to the work machine 10. The target location 60 is represented by the standing tree 65. The tool 30 is intended to grab the tree 65. As shown in
In the examples presented by
In this way, according to a further example of the solution the orienting of the tool 30 takes place by decreasing the angle between the moving direction
According to a further example of the solution, the tool 30 is automatically turned under the control of the control unit 50 of the work machine 10. One or more control signals generated by the control unit 50 are communicated to one or more respective actuators to turn the tool 30. In the examples explained above, the actuator 32 to which the tool 30 is connected is rotated under the control of the generated control signals for turning the tool 30 to a predetermined direction as mentioned above. The control signals may be generated in such a way that the angle between the opening direction Ō and the moving direction
According to the examples described above, the tool 30 is preferably oriented without information or data indicative of the target location 60, e.g. coordinate or two-dimensional information. It is noted that the moving direction
According to a further example of the solution, the location of the target location 60 may be indicated also by other means than by moving the boom 20. Then, information or data indicative of a target location is communicated to the control unit 50 of the work machine 10. According to one example, the operator feeds the necessary information or data to the control unit by using e.g. the control devices of the operator's station. According to a further example, the target location is indicated as coordinate or two-dimensional information having a specific point e.g. in the work machine 10, the boom 20, the tip P or the tool 30 as a reference point known by the control unit.
Thus, based on the indicated information or data, the moving direction
Additionally or alternatively, the operator may feed information or data indicative of the predetermined orientation, e.g. the predetermined angular orientation, of the tool 30, the predetermined orientation relating to one or more examples 1) to 8) mentioned above.
The tool 30 is controlled e.g. according to one or more of the examples 1) to 8) presented earlier. The tool 30 may be turned with respect to the boom 20 in such a way that the angle between the opening direction Ō and the moving direction
In the examples and
Another embodiment of the presented solution will now be discussed with reference to
a to 4d 4b show a work machine 10 having a boom 20 and a tool 30 pivotally mounted to a tip P of the boom 20 via an actuator 32. The work machine 10 with the tool 30 may be a forest machine according to the examples explained above or the forwarder referred to above in the context of
The tool 30 in the examples of
The tool 30 may have the predetermined holding direction
a shows the work machine 10 having the tool 30.
Thus, the holding direction
b shows loading the logs 66 to the load space 13 of the work machine 10 from the pile 67 with logs 66. The load space 13 defines the target location 60. According to the presented example loading situation, the pile 67 may be oriented in such a way that the logs 66 in the pile are perpendicular or transversal to the longitudinal direction of the work machine 10 or the work machine orientation S. Thus, in the example of
The holding direction
It is noted that also other quantities related to the work machine 10, the boom 20 or the tool 30 may be used in connection with the examples presented above when automatically controlling the tool 30. For example, the states of the work machine 10 represented by the loading and unloading situations presented above may be automatically determined by the control unit 50 of the work machine 10. According to another example, the operator feeds the necessary information or data to the control unit by using e.g. the control devices of the operator's station. The information or data in question may select or define the current state of the work machine 10, e.g. from a group of predetermined states. The state selected, defined or automatically determined at each occasion may be used by the control unit 50 to select a predetermined type of control for the tool. According to a further example, the operator feeds information or data to the control unit 50, e.g. by selecting an option from a group of predetermined options, for selecting a predetermined type of control. The predetermined type of control may then be one of the examples 1) to 8) presented above.
Referring to
Referring to
In a similar manner, and referring to
Referring to
According to an example of the presented solution, the location of the tip P of the boom 20 with respect to the work machine location R or a predetermined part of the work machine 10 or the holding direction
For example, the control unit 50 may produce a warning signal, when the holding direction
Additionally or alternatively, the control unit 50 may produce a warning signal when the distance from the tip P to the work machine location R or the predetermined part of the work machine 10 is smaller than a predetermined distance value. Preferably, the tool 30 is in a closed position with one or several logs or tree trunks and the holding direction
Additionally or alternatively, the control unit 50 may be configured to stop or prevent the tool 30 from being controlled to move to a position or orientation resulting to one or more example situations explained above in context with the warning signal. Additionally or alternatively, the control unit 50 may be configured to disable the functioning of the tool 30 or devices in the tool 30 for preventing the actions related to the example situations explained above. The devices in the tool 30 may include the driving devices or the cross-cutting devices mentioned above.
Related to the boom 20 and the various examples presented above, for receiving data or information indicative of at least the moving direction
In the above, the sensor may be a device arranged to measure a value. The sensor may actively send, via a wire or wirelessly, information or data to the control unit 50. In addition or alternatively, the sensor may provide, in response to a signal e.g. from the control unit 50, the information or the data to the control unit 50. The sensor may transmit the information or the data directly or indirectly, e.g. via a link device, to the control unit 50.
An example arrangement of the sensors is presented referring to
Furthermore, the arrangement may comprise one or more sensors to determine the moving direction
Thus, the sensor may be in the form of an acceleration sensor or a navigation system sensor, e.g. a GPS sensor (Global Positioning System). Additionally or alternatively, the moving direction
As will be detailed below, the position of the predetermined point in a boom, e.g. the tip P of the boom 20 depends on the angular relationships of the boom sections of the boom and the dimensioning of the boom sections, i.e. the length of each boom section. According to an example and
Several sensors, optionally of different types, can be used in combination. Furthermore statistical techniques, such as averaging, can be used for improved accuracy. Thus, the information indicative of the quantities mentioned above in the various examples can be provided by at least one, preferably many, sensors chosen from a set of sensors, the set of sensors comprising acceleration, position, velocity, angle, and length sensors. The operational principle of such sensors is wide; e.g. optical, electro-optical, mechanical, electro-mechanical, electrical, and resistive sensors may be used.
Relating to the example case shown in
The presented solution is not limited to the examples and embodiments explained above or presented with reference to the figures. The presented solution is defined by the appended claims.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that any use of the terms “comprises” and/or “comprising” in this specification specifies the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. Explicitly referenced embodiments herein were chosen and described in order to best explain the principles of the disclosure and their practical application, and to enable others of ordinary skill in the art to understand the disclosure and recognize many alternatives, modifications, and variations on the described example(s). Accordingly, various implementations other than those explicitly described are within the scope of the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 14397525.8 | Aug 2014 | EP | regional |
This application claims priority under 35 U.S.C. §119 to European Application No. 14397525.8, filed Aug. 22, 2015, and entire contents of which are incorporated herein by reference.
