RU2028929C1 - Method and apparatus to control hydraulic manipulator - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: process of working unit movement in space, using joint regulation of angular movements of arm and forearm, is exercised by feeding of working fluid from cavity of hydraulic cylinders of arm 3 turning to similar cavity of hydraulic cylinder 4 of forearm 5 turning or vice versa in case angle α₂ of forearm turning is twice as big as angle α₁ of arm turning and total cross section area of arm turning both cylinders similar cavities also is twice as big as cross section area of similar cavities of hydraulic cylinder 4. EFFECT: method and apparatus are used in mechanical engineering. 2 cl, 2 dwg

Description

 The invention relates to the management of hydraulic manipulators used, for example, in the forest industry for supplying timber to woodworking machines or feeding a gripping-cutting device to the trunk of a sawn tree and moving it to the unloading zone in a bag, stack or on a vehicle.

 A known method of controlling a hydraulic manipulator for moving a working body along a path close to rectilinear, consisting in changing the path of the working body in space due to the joint regulation of the angular movements of the shoulder and forearm by simultaneously supplying the working fluid of the shoulder turning cylinder to the same cavity of the forearm turning cylinder or vice versa [1].

 A device for controlling a hydraulic manipulator for moving a working body along a path close to rectilinear, containing a main hydraulic cylinder for turning the shoulder and a hydraulic cylinder for turning the forearm, hydraulic lines for communicating the cavities of the hydraulic cylinders with each other, with a pressure source and with a drain line [2].

 The disadvantages of the known method and device is the complexity of the operations associated with measurements, calculations of coordinates and angles in order to ensure the transfer of the working body along a path close to straight. They require the use of computers, not excluding the manual control of levers and switches.

 The purpose of the invention is to simplify the control process, the design of the device and improve convenience in controlling the movement of the working body in space along a path close to straight.

=

= 2 где λ₁ и λ₂ - угол поворота плеча и предплечья при переносе рабочего органа по траектории, близкой к прямолинейной;
F₁ и F₂ - соответственно площади одноименных полостей гидроцилиндров поворота плеча (суммарная для основного и дополнительного) и поворота предплечья.This is achieved by the fact that the supply of the working fluid from the cavity of the shoulder rotation hydraulic cylinder to the cavity of the forearm rotation hydraulic cylinder of the same name is carried out under the following conditions:

=

= 2 where λ ₁ and λ ₂ - the angle of rotation of the shoulder and forearm when moving the working body along a path close to rectilinear;
F ₁ and F ₂ - respectively, the area of the same cavity of the hydraulic cylinders of the shoulder rotation (total for the primary and secondary) and the rotation of the forearm.

 In the device for controlling the hydraulic manipulator, the goal is achieved in that it is equipped with an additional hydraulic cylinder for turning the shoulder, the cavities of the same name for both hydraulic cylinders for turning the shoulder communicated with hydraulic lines with the corresponding cavity of the hydraulic cylinder for turning the forearm, while the cross-sectional areas of the same cavities for all hydraulic cylinders are equal.

 In FIG. 1 shows a hydraulic diagram of a manipulator; figure 2 is a kinematic diagram of the manipulator.

A device for implementing the method comprises a main 1 and an additional 2 hydraulic cylinders for turning the shoulder 3 and a hydraulic cylinder 4 for turning the forearm 5, at the end of which a working body is installed 6. The cavities of the hydraulic cylinders 1,2 and 4 are connected to the outputs of the spools 7, 8, while the cavities of the same cylinder are of the same name 1 and 2 rotation of the shoulder 3, for example, rod, communicated by hydraulic lines 9 and 10 with the corresponding cavity of the hydraulic cylinder 4 of the rotation of the forearm 5 through an additional spool 11. Moreover, the cross-sectional areas of the same cavities of all hydraulic cylinders are equal among themselves, i.e. the same hydraulic cylinders can be installed to drive the shoulder and forearm: two for turning the shoulder and one for turning the forearm. In this case, the total angles of rotation of the forearm α ₂ and the shoulder α ₁ will also be equal to each other.

где S₂ - ход гидроцилиндра поворота предплечья, а точка крепления его гильзы на плече 3 на расстоянии, равном радиусу r₁ - точки крепления штоков гидроцилиндров на плече. Величина r₁ определяется графически или из известного соотношения:
r₁ ²+r₂ ²-2r₁ ^.r₂.cos(φ_min+ α₂)=(l+2S₂)², где φ_min - минимальный угол между плечом и предплечьем;
l - конструктивный размер, зависящий от конструкции гидроцилиндра и диаметра поршня.The attachment point of the rod of the hydraulic cylinder 4 on the forearm 5 can be located on a radius r ₂ defined by the formula:
r ₂ =

where S ₂ is the stroke of the hydraulic cylinder of the forearm rotation, and the attachment point of its sleeve on the shoulder 3 at a distance equal to the radius r ₁ is the attachment point of the hydraulic cylinder rods on the shoulder. The value of r ₁ is determined graphically or from a known ratio:
r ₁ ² + r ₂ ² -2r ₁ ^. r ₂ .cos (φ _min + α ₂ ) = (l + 2S ₂ ) ² , where φ _min is the minimum angle between the shoulder and forearm;
l - structural size, depending on the design of the hydraulic cylinder and the diameter of the piston.

The liners of the hydraulic cylinders 1 and 2 in this case are fixed on the rack 12 at a radius of r ₂ . The cargo to be handled is indicated by 13, the trajectory of the working body within the full angle α ₂ of the forearm rotation is indicated by 14. At 15–20, spool outputs 7.8 and 11 are indicated.

 The control system for a manipulator that implements the method operates as follows.

To move the working body 6 from the starting point A along path 14 to point B, an additional spool 11 is moved to the right side of the drawing. In this case, the working fluid from the power source through the outlet 15 is fed into the piston cavity of the hydraulic cylinder 4, which at the same time as the forearm 5 is turned, is displaced by its piston from the rod cavity along the hydraulic lines 9 and 10 into the rod cavities of the hydraulic cylinders 1 and 2, and from their piston cavities through the output 16 of the spool 11 is discharged into the tank. Due to the fact that the total area F _{1 of the} rod cavities of the hydraulic cylinders 1 and 2 is two times larger than the area F _{2 of the} rod cavity of the hydraulic cylinder 4, the angle α _{2 of the} rotation of the forearm 5 will be twice as large as the angle α _{1 of the} rotation of the shoulder 3. This allows the worker to move organ in space along a path 14 that is close to rectilinear.

 After the arrival of the working body 6 at the desired point, an additional spool 11 is returned to its original position. Next, move the spool 7 to the right in the drawing side. The working fluid from the power source through the outlet 18 is fed into the rod cavity of the hydraulic cylinders 1 and 2, and through the outlet 17 is discharged from the piston cavities into the tank. In this case, the shoulder 3 lowers the working body 6 to the load 13. After that, the spool 7 is returned to its original position, the load is captured and the spool 7 is again moved now to the left side of the drawing. The working fluid through the outlet 17 is fed into the piston cavity of the hydraulic cylinders 1 and 2, and through the outlet 18 it is discharged into the tank, raising the trapped cargo to a height to move it to the unloading zone - point A. Then, using the additional spool 11, the cargo is moved in the same way as described, which occurs in reverse order.

 Lowering and raising the working body 6 to the load 13 can be carried out using the slide valve 8. In this case, lowering and lifting the working body is carried out using the forearm 5.

Claims (3)

 METHOD FOR HYDRAULIC MANIPULATOR CONTROL AND DEVICE FOR ITS IMPLEMENTATION. 1. The method of controlling the hydraulic manipulator, which consists in changing the trajectory of the working body in space due to the joint regulation of the angles of movement of the shoulder and forearm by simultaneously supplying the working fluid from the cavity of the hydraulic cylinder of turning the shoulder into the same cavity of the hydraulic cylinder of turning the forearm or vice versa, characterized in that the working fluid from the cavity of the hydraulic cylinder of turning the shoulder into the same cavity of the hydraulic cylinder of turning the forearm is carried out when the following Lyrics:

where α ₁ , α ₂ are the angles of rotation of the shoulder and forearm when moving the working body along a trajectory close to straight;
F ₁ , F ₂ - respectively, the area of the same cavity of the hydraulic cylinders of the shoulder rotation (total for the primary and secondary) and forearm rotation;
S ₁ , S ₂ - moves of the hydraulic cylinders of the shoulder and forearm, respectively.  2. A device for controlling a hydraulic manipulator, comprising a main hydraulic cylinder for turning the shoulder and a hydraulic cylinder for turning the forearm, hydraulic lines for communicating the cavities of the hydraulic cylinders with each other, with a pressure source and with a drain line, characterized in that it is equipped with an additional hydraulic cylinder for turning the shoulder, the cavities of the same name both shoulder turning cylinders are communicated by hydraulic lines with the corresponding cavity of the forearm turning cylinder, while the cross-sectional areas of the same name cavities of all hydraulic cylinders are equal.

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