Patent Application
20210400888
The present disclosure generally relates to tree felling heads, and more particularly to a control system and method for controlling the tree felling head coupled to a harvester.
Tree felling heads typically dangle on the end of the stick boom of a forestry machine. After the felling head has cut a tree, an operator has only limited ability to control the felling head in order to influence the direction or force with which the tree falls to the ground.
In one embodiment, a tree felling head is disclosed. The tree felling head is coupled to a boom assembly of a harvester. The tree felling head comprises a frame. A saw is coupled to the frame and is configured to cut a tree. A sensor is provided that senses cutting of the tree by the saw. The sensor outputs a first signal when the tree is cut by the saw. A grapple arm is coupled to the frame. At least one grapple arm actuator is coupled to the frame and the grapple arm. The grapple arm actuator is configured to move the grapple arm between a closed position in which the tree is held by the tree felling head, a gliding position in which the tree is allowed to slide relative to the tree felling head, and an open position in which the tree is released from the tree felling head. A control system is in communication with the grapple arm actuator and the sensor. The control system receives the first signal output by the sensor and outputs a second signal to cause the grapple arm actuator to move the grapple arm to the gliding position when the first signal output by the sensor is received.
In another embodiment, a harvester is disclosed. The harvester comprises an upper frame assembly. A boom assembly is coupled to the upper frame assembly. A tree felling head is coupled to the boom assembly. The tree felling head comprises a frame. A saw is coupled to the frame and is configured to cut a tree. A sensor is provided that senses cutting of the tree by the saw. The sensor outputs a first signal when the tree is cut by the saw. A grapple arm is coupled to the frame. At least one grapple arm actuator is coupled to the frame and the grapple arm. The grapple arm actuator is configured to move the grapple arm between a closed position in which the tree is held by the tree felling head, a gliding position in which the tree is allowed to slide relative to the tree felling head, and an open position in which the tree is released from the tree felling head. A control system is in communication with the grapple arm actuator and the sensor. The control system receives the first signal output by the sensor and outputs a second signal to cause the grapple arm actuator to move the grapple arm to the gliding position when the first signal output by the sensor is received.
In yet another embodiment, a method for cutting a tree with a harvester is disclosed. The harvester is provided with a boom assembly and a tree felling head. The method comprises providing a sensor for sensing when the tree is cut by a saw of the tree felling head. The method further comprises moving a grapple arm of the tree felling head to a gliding position.
Other features and aspects will become apparent by consideration of the detailed description and accompanying drawings.
Before any embodiments are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Further embodiments of the invention may include any combination of features from one or more dependent claims, and such features may be incorporated, collectively or separately, into any independent claim.
As used herein, unless otherwise limited or modified, lists with elements that are separated by conjunctive terms (e.g., “and”) and that are also preceded by the phrase “at least one of” or “one or more of” indicate configurations or arrangements that potentially include individual elements of the list, or any combination thereof. For example, “at least one of A, B, and C” or “one or more of A, B, and C” indicates the possibilities of only A, only B, only C, or any combination of two or more of A, B, and C (e.g., A and B; B and C; A and C; or A, B, and C).
The illustrated work vehicle 100 is a harvester 103. The harvester 103 includes an upper frame assembly 102 which is supported by the tracks 108. The upper frame assembly 102 may include an operator's station 106. Alternatively, the operator may operate the harvester 103 remotely. A plurality of operator inputs (e.g., joysticks, pedals, buttons, screens) for controlling the harvester 103 may be provided in the operator's station 106. The upper frame assembly 102 may also include an engine compartment that houses a prime mover (not shown). The prime mover may be a diesel engine, which provides power for operating the harvester 103.
The upper frame assembly 102 may be mechanically coupled to the undercarriage assembly 104 by a tilt mechanism and turntable assembly 110. The tilt mechanism and turntable assembly 110 operably controls the work vehicle 100 to be rotated and tilted about one or more axes. A swing assembly 112, for example, includes one or more swing motors (not shown) for driving rotation of the upper frame assembly 102 relative to the undercarriage assembly 104. Operation of the swing assembly 112 rotates a platform 120 of the upper frame assembly 102 relative to the undercarriage assembly 104.
With continued reference to
To manipulate the position of the boom assembly 114 with respect to the upper frame assembly 102 the harvester 103 includes a boom actuator 130. One portion of the boom actuator 130 is coupled to the upper frame assembly 102 and another portion is connected to the first boom section 122. A second boom actuator 132 may be coupled to the first boom section 122 and the second boom section 124 to pivot the second boom section 124 with respect to the first boom section 122. A third boom actuator 134 is coupled between the second boom section 124 and the wrist assembly 116. The position of the wrist assembly 116 is controlled by extending or retracting the boom actuator 130, the second boom actuator 132 and the third boom actuator 134. In an exemplary scenario, to raise the wrist assembly 116 the boom actuator 130 is extended which further pivots the boom assembly 114 about the first pivot joint 126.
Referring to
With continued reference to
As illustrated in
In one embodiment, as shown in
A control system 166 is in communication with the grapple arm actuator 152 and the sensor 160. The control system 166 receives the first signal 162 output by the sensor 160 and outputs a second signal 164 to cause the grapple arm actuator 152 to move the grapple arm 146 to the gliding position 156 when the first signal 162 output by the sensor 160 is received. In one embodiment, the control system 166 may include an electronic control unit 168 on the work vehicle 100 that communicates with the sensor 160 by means of a communication bus 170 or a wireless communication 172. The control system 166 may output the second signal 164 to the grapple arm actuator 152 to move the grapple arm 146 to the gliding position 156 for less than ten seconds. Alternatively, the grapple arm 146 may be moved to the gliding position 156 for more or less than 10 seconds. The grapple arm actuator 152 may move the grapple arm 146 to the open position 158 automatically after the set time period elapses.
In another embodiment, the control system 166 may be configured to output the second signal 164 to the grapple arm actuator 152 and the boom actuator 130 to move the grapple arm 146 to the gliding position 156 and move the boom assembly 114 in an upward direction 174 (
The control system 166 may comprise one or more processors 176 and a non-transitory computer-readable storage medium or memory 178 coupled to the one or more processors 176 and storing programming instructions 180 for execution by the one or more processors 176. The programming instructions 180 may instruct the one or more processors 176 to output the second signal 164 to the grapple arm actuator 152 to move the grapple arm 146 to the gliding position 156 when the first signal 162 output by the sensor 160 is received.
Referring now to
The step 182 of sensing when the tree 144 is cut may include a sensor 160 that senses increased pressure when the saw 140 has cut the tree 144 and the tree 144 starts to fall.
The method of cutting the tree 144 with the harvester 103 may further include moving the grapple arm 146 of the tree felling head 118 to the gliding position 156 for less than ten seconds.
The method of cutting the tree 144 with the harvester 103 may further include a step 186 of moving the boom assembly 114 of the harvester 103 in the upward direction 174. Further, the two steps (184 and 186) of moving the grapple arm 146 of the tree felling head 118 to the gliding position 156 and moving the boom assembly 114 of the harvester 103 in the upward direction 174 may be performed simultaneously.
