Hydraulic control system with compensation of hydrodynamic force. RU patent 2509234.

FIELD: machine building.

SUBSTANCE: hydraulic control system (28) is disclosed for a machine (10). The hydraulic control system may include a pump (38), a hydraulic distributor (58) for control of pump efficiency, and also a control hydraulic distributor (68) of a working element made as capable of producing liquid under pressure from the pump and selective direction of the liquid under pressure to a hydraulic motor. The system comprises a controller (34) connected to the hydraulic distributor of efficiency control. The controller may be made as capable of determining pressure drop in the control hydraulic distributor of the working element, substantially differing from the rated pressure drop, determination of the desired position of the hydraulic distributor of efficiency control on the basis of pressure drop, and also determination of hydrodynamic force acting at the hydraulic distributor of efficiency control, on the basis of the desired position. The controller may additionally be made with the possibility of generation of a response signal by determination of the load sent to the hydraulic distributor of efficiency control on the basis of the desired position and hydrodynamic force.

EFFECT: increased accuracy to control a working element of a machine.

10 cl, 3 dwg

The technical field to which the invention relates

The present invention, in General, refers to the hydraulic control system, namely, the hydraulic control system with compensation of the hydrodynamic forces.

The prior art, prior to the invention

The variable pumps are typically used to filing regulated flow of the liquid in the Executive mechanisms of vehicles, such as hydraulic cylinders, or associated with moving bodies of cars or lever mechanisms. Depending on the required flow in the Executive mechanisms of the pump output either increases or decreases so that the Executive mechanisms moved the working bodies and/or lever mechanisms with design speed and/or computational effort. Historically pump production was managed by means of taking into account the load spools control of the type that have been associated with the Executive mechanism of the pump.

Although their use in certain justified cases, the valves control type can have a slow response and to be inaccurate. That is because the valves are triggered by the difference between the desired pressure and the actual pressure, directly affecting the spool, the actual pressure to the actuator at first, during a certain period of time, must come down on a significant value below the desired pressure, will be initiated before any movement of the valve controlling the pump performance. In addition, the movement of the valve, as it is initiated mainly by the difference in pressure at the valve may not provide stable work in different conditions (for example, changing the temperature and viscosity of the fluid). In addition, spools control type can be instability in certain situations because of their slow response time, the instability reduces the precision of control pump output.

In U.S. patent №6374722 issued DN et al. on 23 April 2002, an attempt was made to improve the management capacity of the pump. In particular, this patent describes the installation for the control of hydraulic variable pump. The installation involves managing the servomechanism, managing angle washer pump, hydraulic connected with the control servo-mechanism, and also controls in function of pressure in the discharge line from the pump, controlled by a pressure sensor. Working on the principle of negative feedback loop control servo-mechanism determines its actual position and compares it with the specified position, which is due to a set pressure in the discharge line from the pump. If the control servo-mechanism detects the difference between the calculated position and the actual position is of for adjusting the position of the steering servo until then, until you reach the calculated position. Thus, a built-in effect a negative feedback loop servo-mechanism allows a very precise control of the angle of the washer.

Although the device on this patent allows to increase accuracy of adjustment of the pump discharge, he has certain disadvantages. For example, the device does not take into account hydrodynamic forces acting on the valve during operation of the pump. Therefore, the accuracy of performance and response time can be worse than this is required.

Disclosures the hydraulic control system is aimed at overcoming one or more of the above shortcomings and/or other problems inherent in the prior art.

Summary of the invention

One aspect of the present disclosure of the invention is directed to the hydraulic control system. The hydraulic control system may include the pump is made with the possibility of increase of fluid pressure, the valve performance management designed to affect the productivity of the pump and the regulating valve working body with the possibility of obtaining liquid under pressure from the pump and sample direction of fluid under pressure to the actuator. The hydraulic control system may also include a controller associated with the valve performance management. The controller can be made with the possibility of determining the pressure drop in the control valve of the working body, essentially differs from the calculated differential pressure, to determine the desired slide performance management based on the differential pressure, as well as determine the hydrodynamic forces acting on the valve performance management, based on the desired position. The controller can be additionally completed with an opportunity of formation of the response by definition of load transmitted to the valve performance management based on the desired position and hydrodynamic forces.

Another aspect of the present invention is directed to a method of controlling the flow of the liquid pumped. How can include identifying unwanted pressure difference arising on enforcement of a hydraulic working body, the definition of a desirable value of changes in the performance of the pump based on the undesired pressure drops, and also determination of the hydrodynamic forces that affect the achievement of the desired value of changes in productivity of the pump. How can optionally include feedback on the determination of the load to reach the desired value of changes in productivity of the pump, compensating hydrodynamic forces.

Brief description of drawings

Figure 1 shows a typical machine;

Figure 2 schematically shows a typical hydraulic control system that can be used in the car on figure 1, and

Figure 3 cross-section shows the typical control valve that can be used in the hydraulic control system of figure 2.

Detailed description of the invention

Figure 1 shows a typical variant of implementation machinery 10. The machine can be mobile or stationary machine is able to perform the given operation in specific sectors. For example, the machine 10, depicted in figure 1, can be a front end loader, used in construction. Meanwhile, the machine can be adapted to perform many other tasks in various other areas, e.g. transport, mining industry, agriculture or any other industry, well-known specialists in this field of technology. The machine can include attachments 12 to ensure that the movement of the working body of 14, 16 source of energy, providing the power to attached equipment and cabin 18 operator used for manual and/or automatic control of the mounted equipment.

Attachments may include linkage with one or more hydraulic motors to move the working body 14. In disclosed example hinged equipment includes an arrow 20, rotating about the horizontal axis 22, relative to the working surface 23, one or more hydraulic 26 (1 shows only one), for example one or more cylinders and/or motors. Arrow 20 and can be connected with the working body of the 14 so that when enabled (for example, extension and/or ) hydraulic motors 26, there was a corresponding movement of the working body 14. If necessary attachments may include other and/or additional elements of the lever and/or actuators, differing from shown in figure 1.

The working organ of 14 may include a wide range of various accessories, such as a bucket, plastic d-grip, Bur, traction device (e.g. wheel) or other attached equipment, well-known specialists in this field of technology. The movement of the working body of 14 is carried out by hydraulic motors 26, which can be operated manually and/or automatically from the cab 18 operator.

Cabin 18 operator can be performed with the ability to receive commands from a machine operator about the desired movement of the working body. In particular, cabin 18 operator may include one or more front-end devices 24, made in the form of one - or multi-position handlebars, located next to the operator's chair. The interface device 24 operator can be proportional controllers type, made with the possibility of installation in a certain position, orientation and/or enforcement of the working body of 14 due to the supply of positioning signal for the working body with information about the desired speed and/or the force displacement of the working body. In some cases, the signals interface devices 24, can be used to control the flow, flow direction and/or fluid pressure inside the hydraulic motors 26, thus, controlling the speed, direction of movement and/or efforts of the working body 14. In the cockpit 18 operator, alternatively or in addition, can be installed and other interface devices, such as, for example, wheels, buttons, push and pull devices, switches, pedals and other interface devices operator, known from the prior art.

The energy source 16, shown in figure 2, is connected to the system 28 hydraulic control which controls the operation of hydraulic motors 26. The energy source 16 is made with the possibility of transmission, essentially constant torque and/or speed for the system 28 hydraulic control through the shaft 30. As an option, the source 16 energy can be associated with hydraulic control system 28 other means, such as gears, belt, chain, electric circuit, or other means, is known from the prior art.

The hydraulic control system 28 may include the hydraulic system 32 and controller 34, designed to control fluid flow in the hydraulic system 32. The hydraulic system 32 can consist of various hydraulic components for liquid flow directions. For example, the hydraulic system 32 may include source 36 hydraulic fluid pump 38, driven by 16 source of energy, as well as hydraulic 26, which use liquid under pressure to move a working body of 14 (see figure 1). The controller 34 may communicate with pump-38, hydraulic motors 26 and/or 16 source of energy for selective movement of the working body of the 14 in accordance with the signals received from the interface device 24 operators.

Pump 38 made in the form of a variable pump, equipped with 40 performance management. In one example, the pump can be axial-piston pump with many pigs (not shown), which pushes fluid from the source 36, line 42, and pumping the fluid under high pressure in the line 44 discharge. In this example, the device 40 performance management is inclined washer, which linked the pistons. As of rotation through angle of? tilt washer pistons make back-and-forth motion, providing injection, as described above. Thus, the angle of? tilt the device 40 performance management is directly connected with the displacement of each piston and, ultimately, with the total capacity of the pump 38.

The mechanism 46 tilt can be paired with the device 40 performance management to change the tilt angle of?. One of the examples mechanism 46 tilt can be a hydraulic cylinder, which has the first 48 cavity, which is separated from the second cavity 50 piston 52. First cavity 48 continuously connected to the line 44 discharge line 54, while the second cavity 50 can selectively to communicate with the discharge line, and 36 source feed line 56.

Piston 52 mechanically connected with a 40 performance management to move due to the difference efforts on the piston 52, created by the pressure of the liquid in the first and second cavities 48, 50. For example, if the liquid from the second cavity 50 merges (ie provided hydraulic connection with 36 source with a lower pressure), the piston 52 slides, thereby increasing the tilt angle of?. In turn, if the second cavity 50 is filled with fluid under pressure (ie provided liquid connection with the discharge line 44), the piston 52 promoted, thereby reducing the tilt angle of?. In such an arrangement the amount of fluid inside the second cavity 50, makes the position of the device 40 performance management, whereas the flow of liquid incoming and outgoing from the second cavity 50 determines the speed of movement of the control unit is 40 and, consequently, the rate of change of productivity of the pump 38. Described above the filling and draining of the first and second cavities 48, 50, linked with moves and the extension of the piston 52, optionally can be reversed. If desired, the piston 52 and/or device 40 management performance can deviate spring towards clauses stipulating the specified performance, such as provisions of the minimum or maximum performance.

Valve 58 performance management communicates with the line 44, line 56, as well as through the drain line 60, with 36 source to control fluid flow, entering and leaving the second cavity 50. Valve 58 performance management is one of the many control valves, including, for example, hydraulic distributor with electromagnet control proportional type. As shown in figures 2 and 3, the valve 58 performance management may include the spool 62, movably installed inside 63 and moving, overcoming the spring effect 64, in any of the three working positions by means of a solenoid 66. Solenoid 66 can optionally be powered by the controller 34 to move slide 62 in any desired position.

One of the variants of implementation, shown in figure 3, disc 62 can be spool, of whom at least one band 65 separates the first annular groove 67 from second ring groove 69. The first ring groove 67 is connected to the drain line 60, while the second ring groove 69 associated with the line 44. In the first position (shown in figure 2) belt 65 stops the flow of fluid between the line 44 and line 56, and between 56 and drain line 60. In the first position adjustment of the inclination angle of? does not occur (i.e. the piston 52 hydraulically locked and does not move the device 40 performance management). From the first position shown of figure 2, the solenoid 66 can optionally be supplied to move slide 62 the right, in the second position (is not shown). In the second position of the first ring groove 67 slide 62 connects the line 56 with a drain line 60, thus allowing the liquid to flow from the second cavity 50 in the source 36, relieving pressure in the second cavity 50. In this position, the liquid under pressure in the first 48 cavity makes the piston 52 to vdvinut'sâ, thereby increasing the angle of? tilt the device 40 performance management. From the first position shown of figure 2, the solenoid 66 can optionally be supplied to move slide 62 left in third position (shown in Fig. In the third position of the second ring groove 69 connects the line 56 line 44, thereby allowing the pumped liquid to pass from the pump 38 second cavity 50, increasing in system pressure. In this position, the fluid under high pressure in the second cavity 50, in combination with increased actual area of the piston 52, moves the piston 52 and thereby reduce the angle of? tilt the device 40 performance management. When the valve is 62 moved to the position between the first and second provisions, either in the position between the first and third terms, piston 52 can still adjust the tilt angle of? is proportional to the valve position 62. The fluid passing through the first ring groove 67 and/or through the other with an annular groove 69, may occur at a rate proportional to the actual passage bore A valve spool relevant ring grooves 67, 69. In this description of A valve characterizes, in particular, the smallest area, which passes through the liquid inside the valve 58 performance management.

In figure 2, which shows that the liquid under pressure, the pump discharge 38, can be selectively directed to the hydraulic motors 26 using point 68 of the working body. In particular, the valve 68 working body may be in line 44, in the course before actuators 26. And each of hydraulic motors 26, a similar mechanism of 46 tilt, may include the first and second cavity 70, 72. One of the options for the implementation of the first and second cavity 70, 72 divided by the piston 74. One of the alternative options for the implementation of the first and second cavity 70, 72 can be divided pump wheel or other device power conversion. To move the piston 74 (or other device power conversion) liquid can optionally be made to the first and second cavity 70, 72 or merge of them using point 68 of the working body. For example, if the cavity is filled in by 70 liquid under pressure, and the liquid from the second cavity 72 merges, the piston 74 may vdvinut'sâ for lowering the boom 20 (see figure 1). In turn, if the liquid under pressure from the first cavity 70 merges, and the second cavity 72 filled liquid under pressure, the piston 74 can be nominated for raising arrows 20. For filling and draining of the first and second cavities 70, 72 valve and 68 of the working body can selectively connect line 76 and 78 with the pump exit 38 on line 44, and with 36 source feed - through the drain line pass 80.

Valve 68 working body may be one of the different types of control valves, including, for example, electromagnetic valve proportional type. That is the point 68 of the working body may include the spool 82, for example, moving overcoming the spring effect 84, in any of the three working positions by means of a solenoid 86. One of the options for the implementation of the solenoid 86 can selectively contact spool 82 by means of a spring 88 and be powered by the controller 34 to move slide 82 at any desired position.

Controller 34 related to one or several sensors to increase the precision motion control hydraulic motors 26 and mechanism 46 tilt. In particular, the first probe to 90 can be used to track the pressure pumped 38, such as fluid pressure in the line 44, in the course before the valve 68 working body. The second sensor 92 can be used to track the fluid pressure in the first cavity 70, for example fluid pressure in the line 76. The third sensor 94 similarly can be used to track the fluid pressure in the second cavity 72, for example fluid pressure in the line 78. Sensors 90-94 made with the possibility of formation of signals corresponding tracked pressure, and transmit these signals to the controller 34.

As will be discussed below in more detail, after receiving information from sensors 90-94 and/or from the interface device 24 operator, controller 34 can correct operation of the valves 58 and/or 68 to change movement mechanism 46 tilt and/or hydraulic motors 26. The controller 34 may consist of only a microprocessor or more microprocessors, including controls the operation of the components of the system 28 hydraulic control. Different microprocessors on the market, can be configured for use as a controller 34. Please understand that as the controller 34 may be used as a microprocessor that controls various functions performed by the machine. The controller 34 can be equipped with a memory, the second-only memory, CPU, and any other components for processing applications. The controller 34 can be associated with different systems, such as, for example, power systems, signal processing system, system control solenoid, as well as other systems.

In memory of the controller 34 could be based on one or more cards that are related to various system settings. Each of these cards can include a set of data in the form of tables, diagrams, equations and/or other appropriate form. The card can be selected and/or modified manually or automatically by the controller 34 or operator to change the system operation 28 hydraulic control.

On the basis of signals received from the sensor 90-94, the controller 34 may regulate the operation of the valve 58 performance management to maintain essentially constant ΔP 68 . In particular, the controller 34 can take and compare the signals from the sensors 90-94 pressure to determine ΔP 68 (i.e. to determine the pressure difference between the pressure of the pumped in line 44, and most of the pressure in the lines 76, 78). And if the controller 34 determines that ΔP 68 different from a pre-determined value, i.e. it is not within the desired differential pressure controller 34 generates feedback on the load transmitted to the valve 58 performance management for the correction, P 68 . Feedback on the load from the controller 34 causes solenoid 66 will selectively be supplied to move slide 62 in the desired position, resulting mechanism 46 tilt will adjust the angle of? tilt the device 40 performance management. For example, if ΔP 68 will be less than the specified value, the controller 34 generate a response signal to the load (i.e. supplies current) to the solenoid 66, resulting solenoid 66 moves the valve 62 in the second position, thereby forcing the piston 52 mechanism 46 tilt to vdvinut'sâ, increasing the tilt angle of? and, thus, increasing the productivity of the pump 38. In turn, if ΔP 68 will be greater than the specified value, the controller 34 generate a response signal to the load on the solenoid 66, resulting solenoid 66 moves the valve 62 in the third position, thereby forcing the piston 52 mechanism 46 tilt to move reducing the tilt angle of? and, thus, reducing the capacity of the pump 38. Thus, ΔP 68 can be supported is essentially constant, which ensures the stable operation of the hydraulic 26.

Feedback on the load can be determined/defined/assessed by the controller 34 with cards, memory, and also on the basis of information received from sensors 90-94. In particular, the controller 34 can be made with the possibility of determining the beginning of the desired performance of the pump 38-based ΔP 68 and the desired constant differential pressure. One example of the desired output of the pump 38 may be determined by direct comparison ΔP 68 or comparing the difference between ΔP 68 and desired constant differential pressure with maps stored in the memory controller 34. For another example, certain conditions hydraulic 28, for example the pump speed 38, can be used in conjunction with ΔP 68 to define desired performance pump 38.

On the basis of the known relations between the movement of the device, 40 performance management and change of a specific performance of the pistons inside the pump 38, and on the basis of the known relations between the movement 46 tilt and the resulting angle of? tilt the device 40 performance management, desired performance of the pump can be directly mapped to the desired speed V mechanism 46 tilt. And, as it is well known from the prior art, the rate (i.e. the rate of extension or ) piston (for example, the mechanism 46 skew) can be approximately equal to the flow rate Q liquids coming into the cylinder, divided by the effective area of A cyl affected by the liquid. In addition, because the speed can be determined using maps stored in the memory controller 34, as discussed above, the effective area of the piston 52 known, the flow rate needed to move the mechanism 46 tilt with the desired rate (i.e. the speed necessary to ensure the required pump capacity 38), can be calculated by the following equation 1:

Equation 1

Q=V·A cyl ,

Q - necessary consumption of fluid entering the mechanism 46 tilt;

V is the speed of the piston 52 determined according to the maps controller 34, and

A cyl - known effective area of the piston 52.

It is believed that the fluid passing through the first and/or second ring grooves 67, 69 valve 58 performance management can go with the flow, proportional to the effective area of A valve , the corresponding annular groove of the valve. Thus, having determined using equation 1 above, the flow of fluid, which should arrive in the mechanism 46 inclination to pump 38 responding properly to ΔP 68 , you can program the controller so that it determined should be used as the control valve 58 performance management to meet such expenditure. In particular controller 34 can be made with the possibility of determining the effective area of A valve required for the valve 58 performance management, based on the well-known equations for calculating holes, equation 2 below:

Equation 2

A valve is the effective area of the valve 58 performance management;

Q - necessary consumption of fluid entering the mechanism 46 tilt, and also passing through the control valve 58 performance management determined using equation 1 above;

C d - consumption ratio;

p is the density of the fluid passing through the control valve 58 performance management; and

Δ 58 - pressure drop across the valve 58 performance management.

Flow coefficient C d can be used to viscosity, and the effect of the turbulence of fluid flow and can be in the range from 0.5 to 0.9, in particular through one of the options for the implementation of approximately 0.62. Since the consumption ratio C d , differential pressure ΔP 58 in the valve 58 performance management and the fluid density of p can be essentially constant, A valve is easy to calculate. Meanwhile, it should be noted that although ΔP 58 and p in this example, we can take, essentially, for constant values, it is believed that, at desire, to improve the accuracy of adjustment of the valve can be used measurement data and/or variables.

After calculating A valve controller 34 can determine the force f k , necessary solenoid 66 to move slide 62 on distance x against the spring force 64 to obtain A valve . In particular, in memory of the controller can be based card (for example, performance depending on the curve square), relating known values of A valve with Chi. In accordance with the well-known equation for calculating the force of the spring, equation 3 below, the controller 34 can be executed with the possibility of calculating f k :

Equation 3

f k =x·k

f k is the force required to solenoid 66 to move valve to a distance of 62 % against deflection of the spring action 64;

Chi - distance required to obtain A valve , and

k is the spring 64.

As the movement of the fluid through the control valve 58 performance management, inertia, turbulence and/or viscosity of the fluid may affect the spool 62, you need to take into account to improve accuracy control A valve . Hydrodynamic force affecting the spool 62, can be calculated using equation 4 below:

Equation 4

f f =2·C d ·A valve ·ΔP 58 ·cos(Phi),

f f - hydrodynamic force;

C d - consumption ratio;

A valve is the effective area of the valve 58 performance management;

ΔP 58 - pressure drop across the valve 58 performance management;

Phi - angle outcome of fluid from A valve .

Thus, a return signal is by definition the load sent from the controller 34 to the solenoid 66 in response to ΔP 68 with unwanted value can contain a component related to F s . One of the options for the implementation of the controller 34 may determine, using the card memory (for example, efforts depending on the curve current to the solenoid, 66), the current required for the respective solenoid 66 with the purpose of getting F's . And the controller 34 can be made with the possibility of such a current to the solenoid 66 in response to ΔP 68 .

Industrial applicability

Disclosures the hydraulic control system can potentially be applied to all machines that need a cost-effective and accurate adjustment of the pump performance. Disclosure decision, in particular, can be used in systems with hydraulic working bodies, especially in systems with hydraulic working bodies of mobile machines. Meanwhile, specialist in the art it will be clear that the disclosed hydraulic control system can be used in other machines, include or not include the working bodies with hydraulic control.

During operation of the system 28 hydraulic control for the movement of the working body of the 14 the machine operator can manipulate interface device 24 operators (see figure 1). Because of manipulation of the machine operator interface device 24 may generate the signal is proportional to the corresponding provision interface unit 24. This signal is received by the controller 34 and converted into one or more commands issued by the regulating valve 68 working body, resulting in the spool 82 moves in one of three positions.

With the passage of fluid under pressure by regulating valve 68 working body in the first or second cavity 70, 72 pressure in the relevant lines 76, 78 may vary. The controller 34 can determine pressure drop across the valve 68 (ΔP 68 ) using the signals received from the sensor 90-94 pressure. The controller 34 can compare ΔP 68 with a preset value (i.e. with the desired pressure drop) and generate a corresponding signal response by definition load.

Signal response by definition load may lead to the necessary regulation of the pump performance 38. For example, if the differential pressure ΔP 68 will be too small signal response for determining load may cause the increase of the pump performance 38. In turn, if the pressure differential ΔP 68 will be too large, the feedback on the determination of the load may cause the decrease in productivity of the pump 38.

As discussed earlier, the controller 34 can count/assess/define signal response by definition load of the equations 1-5. In particular, the controller 34 may initially relate ΔP 68 with the desired capacity of the pump 38. Such desired output of the pump, in turn, can be correlated with the desired speed (V) mechanisms 46 tilt, which can be calculated desired flow rate (Q) flow through the valve 58 performance management, using equation 1. On the basis of Q and the estimated constant differential pressure valve 58 performance management (ΔP 58 ) corresponding effective area (a valve), the control valve 58 performance management can be calculated using equation 2. After matching A valve with moving (x) slide 62 using equation 3 can be calculated effort (f k ), which are required by the solenoid 66 to overcome the deflecting force of the spring 64 created Chi. In addition, the effort required by the solenoid 66 to overcome efforts (f f )generated by liquid flow through the valve 58 performance management, can be calculated using equation 4, on the basis of A valve , ΔP 58 and valid constant angle (Phi) of the liquid at A valve . In this case the total force (F s ), required by the solenoid 66, can be calculated using equation 5, and the corresponding element of the team's response signal on the determination of the load may be directed to solenoid 66.

As you can see, the described method and apparatus allow to ensure accuracy in the performance management of the pump for the bill of compensation hydrodynamic forces generated by the movement of the fluid. Compensation hydrodynamic forces allows precise and predictable enforcement of a working body in hydraulic systems with constant pressure. In addition, compensation hydrodynamic forces eliminates the need for servomechanisms for adjustment of provisions used in other systems. By reducing the need for servomechanisms the system allows to reduce the number of errors related to adjustment provisions to improve response pump, increase stability, and reduce costs.

Specialists in this field will be obvious that disclosed in the hydraulic control system can perform various modifications and changes, not going beyond the scope of disclosure of the invention. After reviewing the description of the invention and practical implementation disclosed options for the implementation of the specialists in this field of technology will become apparent to other variants of implementation of the expanded system of the hydraulic management. It is implied that the description and examples should be considered as a model, and the true extent defined in the formula of the invention and its equivalents.

1. The system (28) hydraulic control containing the pump (38)providing fluid injection, hydraulic control (58) the management capacity of the pump (38)regulating valve (68) the working body, made with the possibility of selective direction of fluid under pressure to the hydraulic motor, controller (34)associated with valve control pump output and performed with the ability to determine the differential pressure across the control valve and the working body different from the set pressure differential, determine the correct position of the valve performance management based on the differential pressure, determine the hydrodynamic forces acting on the valve performance management based on the given conditions, as well as the possibility of forming a signal to the load applied to the control valve performance management taking into account the specific conditions and hydrodynamic forces.

2. The system (28) hydraulic control according to claim 1, characterized in that the given condition is the effective area that provides a specified flow rate through the valve performance management and hydrodynamic force is the result of leaking a given fluid flow through the effective area.

3. The hydraulic control system according to claim 2, characterized in that the control valve performance management includes Lopes (62) and spring (64), made with the possibility of displacement of the valve and controller is designed with the ability to determine the linear movement of the valve, ensure the effective area and determining the force applied by a spring to the spool as a result of linear movement.

4. The hydraulic control system according to claim 3, wherein the control valve performance management includes the solenoid (66), made with the possibility of movement of the valve, and the response signal to the load contains information about the amount of effort required by the solenoid to overcome the efforts spring and hydrodynamic force.

5. The hydraulic control system according to claim 2, characterized in that the effective area is calculated from the condition of permanency of the differential pressure in the valve performance management.

6. The hydraulic control system according to claim 5, which includes at least one pressure sensor (90-94)associated with regulating valve and the working body, for measuring the pressure drop in the control valves of the working body.

7. The hydraulic control system of claim 1, comprising the device (40) performance management, made with the possibility of moving to change the pump performance; and a mechanism (46) tilt, made with the possibility of displacement of performance management, and the control valve performance management hydraulically connected with the tilt mechanism, while a specified condition is caused by the specified flow rate passing through the control valve performance management to ensure the desired move tilt mechanism.

8. A method of controlling the flow rate of the pump (38), which includes the determination of undesired pressure drops, resulting from the operation of hydraulic working body; definition of the desired performance of the pump based on the unwanted pressure differential; determination of the hydrodynamic forces affecting the attainment of the desired performance of the pump; and the formation of the response at the load to achieve the performance of the pump, compensating hydrodynamic force.

9. The method of claim 8, wherein the desired output of the pump due to the effective area of the valve, which ensures the desired flow rate for the adjustment of the pump performance; hydrodynamic power is created in the result of passing the desired flow rate through the effective area of the valve; and determination of the hydrodynamic forces includes the determination of the hydrodynamic forces on the basis of effective area of the valve and angle of fluid outflow from the effective areas of the valve.

10. Machine (10), containing: source (16) power supply; working body (14); the actuator (26), made with the possibility of movement of the working body, and also the system (28) hydraulic control on any of the paragraphs. 1 to 7, which is driven by the power supply designed to drive the hydraulic drive (26).