Automatic levelling of a feller head
The present invention concerns a method for the lateral levelling equipment of a timber working head at a forestry machine with a hydraulic system for the driving and regulation of the functions of the forestry machine, which forestry machine comprises a chassis with a driver's cabin and an arm to which a timber working head is fixed jointed and in a manner that allows rotation, the working head comprising levelling equipment and a regulator for the control and regulation of the lateral angle of the working head relative to the vertical direction, an arrangement for the execution of the method, and a forestry machine for the use of the arrangement during the execution of the method.
1. A method for lateral levelling of a timber working head at a forestry machine, wherein the forestry machine comprises a chassis with a driver's cabin and an arm to which the working head is fixed and allows rotation, the working head comprising levelling equipment and a regulator for control and regulation of a lateral angle of the working head relative to a vertical direction, the method comprising:
a) recording a lateral position in the vertical direction, and a zero position corresponding to a vertical plane in the vertical direction, of the working head;
b) bringing the working head out of the zero position;
c) recording, by the levelling equipment, a deviation of the working head from the zero position, the deviation corresponding to the lateral angle defined between a longitudinal direction of the working head and the vertical plane when the working head tilts laterally away from the vertical plane in a direction that is transverse to a horizontal direction extending through the arm;
d) generating, by the levelling equipment, a deviation signal;
e) transmitting the deviation signal to a signal processor and receiving, by the signal processor, the deviation signal;
f) defining, by the signal processor, the deviation from the zero position;
g) transmitting, by the signal processor, a correction signal to a computer of a hydraulic system at the forestry machine; and
h) maneuvering, by the regulator, the working head to the zero position.
2. The method according to claim 1 , whereby the steps a)-h) are continuously repeated.
3. An arrangement for lateral levelling of a timber working head at a forestry machine, wherein the forestry machine comprises a chassis with a driver's cabin and an arm to which a working head is fixed and allows rotation, the arrangement comprising:
a levelling equipment for control of a lateral angle of the working head relative to a vertical plane, the lateral angle defined between a longitudinal direction of the working head and the vertical plane when the working head tilts laterally away from the vertical plane in a direction that is transverse to a horizontal direction extending through the arm;
a signal processor that generates a signal based on an angular deviation from the vertical plane; and
a regulator for regulation of the working head in alignment with the vertical plane.
4. The arrangement according to claim 3 , whereby the levelling equipment comprises an angular sensor.
5. The arrangement according to claim 3 , whereby the levelling equipment comprises a pressure sensor.
6. The arrangement according to claim 3 , whereby the levelling equipment comprises a gyroscope.
7. The arrangement according to claim 3 , whereby the signal processor comprises a calculation computer and a control computer.
8. The arrangement according to claim 3 , whereby the regulator comprises a rotator.
9. The arrangement according to claim 3 , whereby the regulator comprises a hydraulic piston-cylinder unit.
10. The arrangement according to claim 3 , whereby the regulator comprises an electric motor.
11. The arrangement according to claim 3 , whereby the levelling equipment is arranged at the timber working head.
12. The arrangement according to claim 3 , whereby the levelling equipment is arranged at the forestry machine.
13. The arrangement according to claim 3 , whereby the regulator can be switched off by a control stick or button located in the driver's cabin.
14. A forestry machine comprising the arrangement according to claim 3 .