A work machine (1) comprises at least one structural element (21), at least one pressure medium operated actuator 22) for establishing at least one operation of the work machine, and at least one detection device (23) to determine the position of the structural element (21) of the work machine. An arrangement for controlling at least one operation of the work machine (1) comprises: a control valve arrangement (24) for controlling the actuator (22), and a control device (25) for controlling the control valve arrangement (24). The control device (25) is adapted to control said control valve arrangement (24) for adjusting the pressure and/or volume flow on the return line of the actuator (22) as dependent on the position of the structural element (21).

The improved thinning or clearcut head is configured a tree harvesting vehicle supported by a plurality of wheels and tires. The improved thinning or clearcut head is adapted for use in cutting down a target tree. The improved thinning or clearcut head comprises a tree harvesting vehicle and a lateral pivot apparatus. The tree harvesting vehicle comprises a harvest vehicle and a cutting tool. The lateral pivot apparatus attaches the cutting tool to the harvest vehicle such that the cutting tool rotates around a lateral axis of rotation that is parallel to the center axis of the target tree. The improved thinning or clearcut head aligns the cutting tool with the target tree such that the alignment axis between the clamping arms of the cutting tool and the target tree is offset from primary sense of direction of the harvest vehicle.

The improved thinning or clearcut head is configured a tree harvesting vehicle supported by a plurality of wheels and tires. The improved thinning or clearcut head is adapted for use in cutting down a target tree. The improved thinning or clearcut head comprises a tree harvesting vehicle and a lateral pivot apparatus. The tree harvesting vehicle comprises a harvest vehicle and a cutting tool. The lateral pivot apparatus attaches the cutting tool to the harvest vehicle such that the cutting tool rotates around a lateral axis of rotation that is parallel to the center axis of the target tree. The improved thinning or clearcut head aligns the cutting tool with the target tree such that the alignment axis between the clamping arms of the cutting tool and the target tree is offset from primary sense of direction of the harvest vehicle.

The invention relates to a system for remote and/or autonomous holding at least a portion of a tree trunk, said system comprising: a remotely and/or autonomously controlled Unmanned Aerial Vehicle (100), UAV, at least one remotely and/or autonomously controlled means (105) for holding at least a portion of a tree trunk attachable to said UAV (100), means for detecting at least a portion of a tree, means for detecting at least one tree parameter of at least a portion of a tree and/or at least one growing condition of at least a portion of a tree, a base station for communication with said UAV (100), means configured for directing said means (105) for holding at least a portion of a tree trunk to a particular position of said tree trunk depending on said at least one detected tree parameter and/or said at least one detected growing condition.

The invention relates to a system for remote and/or autonomous holding at least a portion of a tree trunk, said system comprising: a remotely and/or autonomously controlled Unmanned Aerial Vehicle (100), UAV, at least one remotely and/or autonomously controlled means (105) for holding at least a portion of a tree trunk attachable to said UAV (100), means for detecting at least a portion of a tree, means for detecting at least one tree parameter of at least a portion of a tree and/or at least one growing condition of at least a portion of a tree, a base station for communication with said UAV (100), means configured for directing said means (105) for holding at least a portion of a tree trunk to a particular position of said tree trunk depending on said at least one detected tree parameter and/or said at least one detected growing condition.

The present invention relates generally to an improved tree processing system enabling efficient, reliable and accurate processing of harvested trees. The system includes a grabbing head having first grabbing arms and a delimbing head having second grabbing arms. The first and second grabbing arms are mounted on a boom system and can be activated to grab the tree stem of a harvested tree. When grabbed, the boom system can be selectively extended or retracted to effect delimbining of a felled tree. Each of the delimbing head and grabbing head includes saws allowing an operator to selectively activate one or both saws to cut a length of timber.

The present invention relates generally to an improved tree processing system enabling efficient, reliable and accurate processing of harvested trees. The system includes a grabbing head having first grabbing arms and a delimbing head having second grabbing arms. The first and second grabbing arms are mounted on a boom system and can be activated to grab the tree stem of a harvested tree. When grabbed, the boom system can be selectively extended or retracted to effect delimbining of a felled tree. Each of the delimbing head and grabbing head includes saws allowing an operator to selectively activate one or both saws to cut a length of timber.

A rotation device arrangement includes a structure and a suspension part for suspending the rotation device from a boom. The structure includes a first inner body part and first conduits for leading a pressure medium through the first inner body part. A second outer body part is arranged at least partly around the first inner body part completely rotatably. First connections are fitted for leading the pressure medium through the second outer body part. Second conduits are fitted to at least one of an outer surface belonging to the first inner body part and an inner surface belonging to the second outer body part for leading the pressure medium from the first conduit to the first connections. A bearing is arranged to permit the second outer body part to rotate and to carry loads axially and radially. Second connections attach a direct-drive pressure-medium operated turning device to the structure coaxially to transmit torque.

A forestry machine includes a ground propulsion apparatus, a vehicle body supported by the ground propulsion apparatus, an operator seat disposed on the vehicle body, a first control lever operable by an operator sitting in the operator seat, a work implement including a saw, and a control circuit. The control circuit includes a first user input disposed on the first control lever. The first user input is operatively coupled to the work implement. Power to the saw is engaged upon the first user input being operated in combination with another operation. A method of operating a forestry machine includes operating a first user input disposed on the first control lever. Power is engaged to the saw in response to the first user input being operated in combination with another operation.

A self-propelled work vehicle is provided with work state estimation and associated control techniques. The work vehicle comprises ground engaging units, a work implement configured for controllably working terrain, and various onboard sensors. A controller is functionally linked to at least the one or more onboard sensors and configured to ascertain a first parameter or operation of the work vehicle, determine a work state of the work vehicle, based at least in part on respective input signals from one or more onboard sensors, and generate a control signal for controlling at least a second parameter or operation of the work vehicle, responsive to the ascertained first parameter or operation and the determined work state. The control signals may be provided for proactive adjustments to engine speed, movements of the work implement, movements of the work vehicle itself, etc.