CN116583687A - Hydraulic pump for hydrostatic drive and hydrostatic drive - Google Patents

Hydraulic pump for hydrostatic drive and hydrostatic drive Download PDF

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Publication number
CN116583687A
CN116583687A CN202180084417.9A CN202180084417A CN116583687A CN 116583687 A CN116583687 A CN 116583687A CN 202180084417 A CN202180084417 A CN 202180084417A CN 116583687 A CN116583687 A CN 116583687A
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CN
China
Prior art keywords
hydraulic pump
time derivative
target
pressure
des
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CN202180084417.9A
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Chinese (zh)
Inventor
S·穆奇勒
M·希尔施
A·特拉齐特
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Robert Bosch GmbH
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Robert Bosch GmbH
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Publication of CN116583687A publication Critical patent/CN116583687A/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/38—Control of exclusively fluid gearing
    • F16H61/40—Control of exclusively fluid gearing hydrostatic
    • F16H61/42—Control of exclusively fluid gearing hydrostatic involving adjustment of a pump or motor with adjustable output or capacity
    • F16H61/421—Motor capacity control by electro-hydraulic control means, e.g. using solenoid valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
    • F04B49/06—Control using electricity
    • F04B49/065—Control using electricity and making use of computers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/38—Control of exclusively fluid gearing
    • F16H61/40—Control of exclusively fluid gearing hydrostatic
    • F16H61/46—Automatic regulation in accordance with output requirements
    • F16H61/472—Automatic regulation in accordance with output requirements for achieving a target output torque
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B2205/00—Fluid parameters
    • F04B2205/09—Flow through the pump

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Computer Hardware Design (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Control Of Positive-Displacement Pumps (AREA)
  • Operation Control Of Excavators (AREA)

Abstract

A hydraulic pump with an adjustable delivery volume is disclosed for pressure-controlled supply of a hydrostatic load, comprising a trajectory planning unit, by means of which a target trajectory with flatness and its time derivative can be planned from the pressure of the hydraulic pump that can be requested, and which can be transmitted to a pre-control unit of the hydraulic pump, which comprises a reverse model of the hydraulic pump, by means of which a control target value of an adjusting device of the hydraulic pump can be determined from the target trajectory and its time derivative, and by means of which the adjusting device can be controlled. Furthermore, a hydrostatic drive is disclosed, which has a hydraulic pump and a hydrostatic load supplied by the hydraulic pump with a pressure medium.

Description

Hydraulic pump for hydrostatic drive and hydrostatic drive
Technical Field
The present invention relates to a hydraulic pump according to the preamble of claim 1 and a hydrostatic drive, in particular a travel drive, according to claim 16.
Background
In particular in the off-road sector of hydrostatic travel drives, traction-or torque-based travel strategies have proven to be operator-friendly. Here, the operator presets the traction or torque request by means of the HMI interface. The traction force or torque produced is hydraulically based on the pressure of the pressure medium provided by the hydraulic pump. In the case of a rotary load, the hydrostatic load coupled to the output device or the traction force or torque of the hydraulic motor is derived on the basis of the pressure and as a function of the absorption volume. Instead, traction or torque based actuation can be achieved by means of pressure control or regulation.
Publication DE 102014224337A1, which originates from the applicant, shows a travel drive of this type. Here, the control is performed with the preset of the torque target value at the output device as the control parameter. According to the presets, the planning of the target time profile or the target trajectory can be realized not only from the target value, but also from the time derivative of the target value, which can be carried out by the mechanism of the drive. The trajectory is then input into a complex inverse model of the entire hydraulic circuit, i.e. the hydraulic pump and the hydraulic motor. The target trajectory of the adjustment variable is thereby planned by the control unit for achieving the target value. Manipulation of the adjustment element of the travel drive is then effected as a function of the target trajectory. This is a high quality control. However, the model on which it is based is complex.
Disclosure of Invention
In contrast, the object underlying the invention is to create a hydraulic pump for a drive device, by means of which the pressure for the drive device can be set with reduced effort and nevertheless closely guided by a force or torque setting. A further object of the invention is to provide a drive whose force or torque can be set with reduced effort and closely guided by a force or torque setting.
The first task is solved by a hydraulic pump having the features of claim 1 and the second task is solved by a drive device having the features of claim 16.
Advantageous developments of the invention are described in the dependent claims.
The first hydraulic machine, which can be operated as a hydraulic pump and can be coupled to the drive machine (hereinafter hydraulic pump), has an adjustable delivery volume and is provided for pressure medium supply of the hydrostatic load of the drive, in particular of the travel drive, in a pressure-controlled manner (druckgef u hrt). The hydraulic pump is in particular a primary unit of an axial piston pump in the form of a swash plate. The load is in particular a hydraulic motor which can be coupled to the output of the drive. The hydraulic pump has means for trajectory planning. By means of which a target trajectory featuring flatness (flichheit) and its time derivative can be planned for the required pressure. These target trajectories are input into a device for pre-control of the hydraulic pump, which comprises an inverse model of the hydraulic pump. By means of the device and the inverse model, a control target value of the adjusting device for the hydraulic pump can be determined from the target trajectory and its time derivative, and the adjusting device can be controlled thereby. According to the invention, at least one load-dependent disturbance variable is fed to the pre-control unit. These interference parameters can preferably be detected, detected or known from the control.
It can therefore be dispensed with in relation to the cited prior art that the load is entirely modeled and integrated into the inverse model. Thus, the inverse model has a lower complexity. In order to nevertheless achieve a high quality of control, i.e. to keep the pressure deviation from the desired value small, the disturbance variable of the load is fed to the pilot control. A hydraulic pump is thus achieved, by means of which the pressure for the drive can be set with reduced effort and nevertheless closely guided by the force or torque setting.
In a variant, the absorption volume of the load, in particular of the hydraulic motor, can be controlled, detected or determined, i.e. known, by the control.
The time constant of the trajectory planning depends inter alia on the use situation, i.e. on the specific application of the hydraulic pump in the specific drive.
Alternatively or additionally, input saturation and/or state saturation can be taken into account in the device for trajectory planning for calculating the respective trajectory.
The inverse model is based on a reduced order model of differential equations of the hydraulic pump, which is composed of differential equations for describing the adjusting device and differential equations (pressure build equations) for describing the pressure build. If the adjusting device is formed by a hydraulic actuator, in particular a hydraulic cylinder, and a hydraulic valve for applying a control pressure medium to the hydraulic actuator (as described further below), the dynamics of the valve adjustment can be ignored. The differential equation of the adjusting device is then derived from the corresponding force balance at the valve body and at the piston of the actuator. Alternatively, valve dynamics may be considered.
In a modification, the at least one load-dependent disturbance variable is the detected or ascertained pressure medium volume flow of the load or a time derivative of the pressure medium volume flow. Alternatively, two mentioned variables, namely the pressure medium volume flow and its time derivative, can be fed as interference variables.
In a modification, the inverse model comprises a volume flow model or a volume flow balancing mechanism, the output of which is a target delivery volume, in particular a geometric variable, that determines the hydraulic pump. In the case of axial piston pumps of the swash plate design, this variable is, for example, the pivot angle of the swash plate.
According to a preferred variant, the following objects are provided as inputs into the volume flow model or the volume flow balancing mechanism: at least one detected or ascertained delivery volume flow of the hydraulic pump from the rotational speed and the variable, the first time derivative of the target trajectory, and the pressure medium volume flow of the load as a possible feed-in, load-dependent disturbance variable.
In a modification, the inverse model has a volumetric flow time derivative model or a volumetric flow time derivative balancing mechanism. The output of the inverse model is the time derivative of the target delivery volume, in particular of the geometric parameter, of the hydraulic pump, in particular of the pivot angle mentioned above.
The input to the volume flow time derivative model or to the volume flow time derivative balancing means is preferably the at least one detected or derived delivery volume flow of the hydraulic pump, the first time derivative of the target trajectory, the trajectory dependent on the second time derivative of the target trajectory, and the time derivative of the pressure medium volume flow of the load as a possible disturbance variable dependent on the load.
The quality of the pre-control can also be improved if in a modification the inverse model comprises a leakage model. This leakage model preferably takes as input at least the target trajectory and the first time derivative of the target trajectory. The output is preferably a leakage pressure medium volume flow, in particular of a particularly hydrostatic drive of a hydraulic circuit comprising at least a hydraulic pump and at least one hydraulic motor; and the time derivative of the volumetric flow of the leakage pressure medium. In a modification, this leakage pressure medium volume flow is then fed into a volume flow model or a volume flow balancing device.
Alternatively or additionally, the time derivative of the volumetric flow of the leakage pressure medium can be fed into a volumetric flow time derivative model or a volumetric flow time derivative balancing mechanism in order to further improve the quality of the pre-control.
In a variant of the hydraulic pump, a better quality is achieved with the adjusting device, since this allows for model inaccuracy, model uncertainty and unknown disturbance variables and more reliable reduction of the pressure deviation from the desired pressure.
For this purpose, a first comparison means is provided, by means of which a first difference can be determined from the target trajectory (subtracted) and the detected pressure (subtracted). The first difference is then in turn an input into the regulating device.
The adjustment device preferably reflects an adjustment strategy which, for example, allows an operator-requested traction force/requested torque to be applied to the drive wheels of the drive device.
For this purpose, PID control devices are provided in particular.
The PID controller is preferably designed with the aid of an Anti-saturation (Anti-Windup) in terms of controlling the saturation of the target value and determining the saturation of the geometric variable (in particular the pivot angle) of the delivery volume of the hydraulic pump. When the variable (pivot angle) reaches a defined threshold value, which is stored in the pre-control unit, saturation can preferably be activated due to the limited pivot angle. Additionally, the PID regulator can be reset when the parameter (pivot angle) exceeds zero, since the integral of the PID regulator depends in part on the valve used. The desired characteristics of pressure are described by the linearized function z and its first and second time derivatives.
In order to process the output of the regulating device and to feed it back to the pre-control, a second comparison means is provided in a modification. The inputs to the second comparison mechanism are: the second time derivative (subtracted) of the target trajectory and the output (subtracted) of the regulating device, which have already been mentioned above. The output of the second comparison means is the previously mentioned relevant trajectory. In this way the second time derivative of the target trajectory is changed from the output of the regulating device to the relevant trajectory. In particular, the output of the PID regulator is calculated with the highest order time derivative of the target trajectory of the required pressure, which is then the new input into the inverse model. The advantage of this configuration is that the variation of the gain of the tuning system is taken into account by the inverse model. Thus, for example, only a small increase in the actuation target value and the pivot angle is required for high rotational speeds of the hydraulic pump, whereas a larger increase is required for low rotational speeds.
As already indicated, in a preferred variant, the adjusting device has a hydraulic actuator, in particular a hydraulic cylinder. For this purpose, electromagnetically actuated hydraulic valves are provided which can be actuated by actuating currents. Depending on the actuation of the hydraulic valve, the actuator can be acted upon with a pressure medium volume having a regulating pressure.
For this purpose, the target adjustment pressure can be determined from the characteristic curve of the hydraulic pump set in the inverse model. The characteristic curves describe the dependence of the target control pressure on the rotational speed of the hydraulic pump, the target trajectory and parameters (in particular the pivot angle) that determine the target delivery volume of the hydraulic pump. In contrast, the target control pressure medium volume can be determined from a model of the actuator, which is arranged in an inverse model and reflects the correlation of the target control pressure medium volume with the time derivative of the variable (in particular the pivot angle) that determines the target delivery volume.
In a modification, the hydraulic valve is electromagnetically actuable, and the inverse model comprises a model of the valve, by means of which a target actuating current of the valve can be determined as a function of the target actuating pressure and the target actuating pressure medium volume. The valve model represents, in particular, the force balance of the magnetic force, the flow force, the actuating pressure and, if appropriate, the spring force acting on the valve piston.
The hydrostatic drive has a hydrostatic load which can be coupled to an output of the drive; and has a hydraulic pump designed according to the previously described aspects, which is fluidly connected to the load in a hydraulic circuit and can be coupled to a drive machine of the drive device.
In particular, the drive is a travel drive and the load is a hydraulic motor. Thus, a traction or torque-based driving strategy can be implemented for a travel drive without requiring adjustment, with high quality and reproducibility of the torque requested by or the traction requested by the operator. Of course, the quality and reproducibility can also be improved by the adjusting device already described and modifications of the adjusting device.
Hydrostatic travel drives are provided, in particular, for off-highway applications, in particular mobile work machines, in particular work machines. At least one load is in particular a secondary unit of an axial piston motor, which is designed in the manner of a tilt-axis design, in particular with a constant or adjustable absorption volume. The two units (primary and secondary) are fluidly connected in series. The hydraulic pump is driven in the drive by an internal combustion engine, an electric energy store, a hydraulic pressure store or the like and converts mechanical power into hydraulic power. At least one secondary unit converts hydraulic power to mechanical power on the output side of the drive. The process can also be performed in reverse, so that at least one secondary unit is braked on the output side. The hydraulic circuits of the primary unit and the secondary unit can be implemented as an open circuit or as a closed circuit. In the case of an open circuit, the low pressure side of the unit is connected to a pressure-balanced storage tank; in a closed circuit, the low-pressure side of the primary unit and the low-pressure side of the secondary unit are directly connected to each other. Both circuits are preferably protected against excessive pressure by pressure limiting valves. In order to increase the efficiency of the drive, a power branch can be provided, wherein a mechanical power path is provided in parallel to the hydrostatic section of the drive. The adjustment in terms of the discharge volumes of the primary unit and the secondary unit may be separate or coupled to each other. In general, a rotational speed proportional to the pressure medium volume flow is produced on the secondary side.
Drawings
An embodiment of the drive device according to the invention with a hydraulic pump according to the invention is explained in detail below with three figures. Wherein:
FIG. 1 illustrates a hydrostatic drive configured as a progressive drive in accordance with one embodiment;
fig. 2 shows a simplified block diagram of a hydraulic pump of the drive according to fig. 1 together with its device for track planning, pre-control and regulation, and
fig. 3 shows a detailed block diagram of the hydraulic pump according to fig. 2.
Detailed Description
According to fig. 1, a hydrostatic travel drive 1 has a drive machine 2; a first hydraulic machine 4 (hereinafter hydraulic pump) coupled to this drive machine and designed as an axial piston pump in the form of a swash plate with an adjustable delivery volume or pivot angle; and a second hydraulic machine 8 (hereinafter hydraulic motor) with constant displacement or shaft angle, designed as an axial piston motor in a diagonal configuration, coupled to the output device 6. In the embodiment shown, the hydraulic pump 4 and the hydraulic motor 8 are in fluid connection in a closed hydraulic circuit via working lines 10, 12. The hydraulic motor 8 is coupled to the output device 6 via a transmission 14. In the illustrated embodiment, the output device is a shaft with wheels 16.
The drive 1 has means 18 for detecting a geometric variable that determines the delivery volume of the hydraulic pump 4. In the mentioned embodiment, these variables are, for example, the pivot angle α of the swash plate of the hydraulic pump 4.
Furthermore, means 20 are provided for detecting the pressure p of the hydraulic pump 4, more precisely the pressure difference Δp between the working lines 10, 12 on the hydraulic machine 4. Based on the arrangement in the hydraulic circuit and with negligible flow losses, the pressure p drops by the same magnitude as the pressure difference Δp over the hydraulic motor 8. Furthermore, the hydraulic pump 4 has an adjusting device 22 for adjusting the pivot angle α of the hydraulic pump and thus the delivery volume.
In the exemplary embodiment shown, the actuating device is formed by an electromagnetically actuated hydraulic valve (not shown in the exploded view) and an actuator (likewise not shown in the exploded view) which can be acted upon by the hydraulic valve with a control pressure medium and is designed as a double-acting hydraulic cylinder.
Adjustment is known in particular as electric direct adjustment or ET adjustment. The volumetric flow rate of the pressure medium of the hydraulic pump 4 can be controlled by the hydraulic valveControlled steering current i des To adjust steplessly. In this case, a valve, in particular a pressure relief valve, can be provided for each adjustment direction (in particular if the hydraulic pump 4 can be turned around or back due to its zero delivery volume). To and control the current i des Proportional relation to load the actuator with the regulating pressure medium. Based on the characteristic curve of the hydraulic pump 4, the control current i is set to be specific des The pivoting angle that occurs and the transport volume determined therefrom depend on the rotational speed n P And a pressure difference Δp.
The hydraulic pump 4 has a control unit 24 according to the invention, which comprises a device for path planning of the pressure difference and its time derivative, for feeding in according to disturbance variables with the hydraulic motor) Means for pre-controlling the hydraulic pump 4 and means for regulating the pressure. The control unit 24 is in signal connection with a control unit 26 of the drive machine 2.
Fig. 2 shows a general structure of the control unit 24 and a first overview of the signal flow with respect to the control unit. The control unit 24 therefore has an input 28, which can be connected, for example, to an interface of the HMI, via which a desired pressure difference Δp can be made available des (hereinafter briefly expressed as the required pressure Δp des ) Is passed to the control unit 24. Pressure Δp des Traction force F requested by the operator via HMI, representing the travel drive 1 des Or required output torque M des Intensity (intentive) state parameter of (a) a vehicle. The pressure is therefore a control variable or regulating variable to be set as precisely as possible by the control unit 24. According to fig. 2, this pressure is fed into a device for trajectory planning (trajektoroienplanung) 30, which has a pressure Δp des，filt And its two time derivativesAs a flat, linearized output. Three purposesTrace Δp des，filt 、/>Is fed into a device for a pre-control (Vorsteuerung) 32, wherein the highest order time derivative +.>Can be changed in advance by the means for adjusting 34, which will be explained in detail below.
The device for pre-control 32 comprises an inverse model of the hydraulic pump 4, comprising the adjusting device 22 of the hydraulic pump with the valve and the actuator according to fig. 1. The pressure medium volume flow of the hydraulic motor 8 and its time derivative are fed as disturbance variables to the device for the pre-control 32. The pre-controlled output 36 provides the steering current i des The valve of the adjusting device 22 is actuated by this actuating current, and thus its actuator is acted upon by the actuating pressure medium, and the pivot angle α of the hydraulic pump 4 is adjusted.
The pressure Δp that occurs is detected and fed back as a reduction to the first comparison means 38, where it is correlated with the pressure Δp des，filt Is calculated.
The deviation determined in this case is fed to a device for the regulation 34, which is designed as a PID controller. The output of the device is in turn connected as a reduction to the second comparison means 40 and there to the time derivative of the highest order of the pressureIs calculated. The result is then an altered target path of the highest-order time derivative of the pressure, which is fed into the device for the pre-control 32 and which leads to an altered actuating current ides with which the valve of the regulating device 22 is actuated. A new pressure Δp is thus created.
Fig. 3 more precisely breaks up the means for pre-controlling 32 and the models and signal flows stored therein. Thus, the inverse model of the hydraulic pump 4 is saved in the means for pre-control 32.
This inverse model comprises a characteristic curve 42 of the hydraulic pump 4, in which the rotational speed ω for the hydraulic pump 4 is P Pressure Δp des，filt Is provided, the necessary target pivot angle alpha of the hydraulic pump 4 P，soll The necessary target actuating pressure p of the actuator of the actuating device 22 is saved x，soll 。
Furthermore, an actuator model 44 is provided, in which the time derivative for the target pivot angle of the hydraulic pump 4 is providedThe necessary target adjustment pressure medium volume q of the actuator of the adjustment device 22 is saved stell，soll 。
The characteristic curve 42 and the actuator model 44 are models of components close to the drive and represent, in particular, the drive forces, pressures and actuating pressures acting on the swash plate of the hydraulic pump 4. The resulting, necessary target control pressure p x，soll The value of (2) and the target adjustment pressure medium volume q of the actuator stell，soll Into a valve model 46 of the valve of the adjusting device 22.
This represents a force balance of the forces acting at the valve body of the valve. Target regulation pressure p x，soll And the piston area of the actuator are fed to a module 48 for determining the pressure Fp. Target regulation pressure p x，soll And a target adjustment pressure medium volume q of the actuator stell，soll Into a module of valve opening cross section 50. The module 50 thus calculates the spring force F F And flow force F jet . The sum of these three forces corresponds to the actuating force F to be applied by the electromagnet of the valve of the adjusting device 22 M And is fed to a module for determining the actuating current 52, in which the actuating current i is stored in principle des Is related to the operating force F M Is a characteristic curve of (2).
Furthermore, the means for pre-controlling 32 comprises a volume flow model 54, a volume flow time derivative model 56 and a leakage model 58.
The rotation speed is setω P First order time derivative of target trajectoryVolumetric flow rate q of leakage pressure medium leck The pressure medium volume flow q of the hydraulic motor 8 as a disturbance variable mot Is input into the first-mentioned model 54. The result of the volumetric flow model 54 is a target pivot angle α P，soll The target pivot angle is input into the characteristic curve 42 for adjusting the pressure p to the target x，soll The above-described determination was performed.
The rotation speed omega P The highest order time derivative of the target trajectory, which varies after the second comparison means 40First order time derivative of the target track +.>Time derivative of the volumetric flow of the leakage pressure medium +.>And the time derivative +_of the pressure medium volume flow of the hydraulic motor 8 as disturbance variable>Into the mentioned second model 56. The result of the volumetric flow time derivative model 56 is the time derivative of the target pivot angle +.>Input into the actuator model 44 for adjusting the pressure medium volume q to the target stell，soll The above-described determination was performed.
Volumetric flow rate q of leakage pressure medium leck And its time derivativeFrom leakage models58 according to the target trajectory Δp des，filt And its first time derivative->To be solved and provided.
Models 54, 56, and 58 can be referred to as hydraulic model 60.
By operating current i des Manipulation of the valve of the regulating device 22 thus generates a pressure Δp, which is fed back to the PID control 34 for the purpose of regulating the residual deviation, as already described with reference to fig. 2.
A hydraulic pump for the pressure medium supply of a hydrostatic load (in particular a hydraulic motor) of a hydrostatic drive (in particular a travel drive) is disclosed, comprising a control unit having a device for trajectory planning of a target pressure of the hydraulic pump and its time derivative, wherein the target trajectory is an input to a device for pre-control, in which a reverse model of the hydraulic pump is stored, by means of which a control target value of an actuating device of the hydraulic pump can be determined from the trajectory and by means of which this actuating device can be actuated, wherein at least one input into the reverse model is provided according to the invention for feeding in an interference variable dependent on the load.
Furthermore, a hydrostatic drive, in particular a travel drive, is disclosed, having at least one hydrostatic load which can be coupled to an output of the drive, which hydrostatic drive is arranged in a hydraulic circuit together with a hydraulic pump as mentioned last and can be supplied with a pressure medium by the hydraulic pump, wherein at least one state variable of the load is fed as a disturbance variable to a pre-control of a control unit of the hydraulic pump.

Claims (16)

1. Hydraulic pump with adjustable delivery volume for pressure-medium supply to a hydrostatic load (8) in a pressure-controllable manner, comprising a path planning unit (30) by means of which it is possible to implementThe pressure (Δp) which can be requested by the hydraulic pump (4) des ) For a target track (Δp) having flatness des，filt ) And the time derivative of the target trajectoryPlanning is carried out and can be transmitted to a pre-control unit (32) of the hydraulic pump (4), which comprises at least an inverse model (42, 44, 46, 60) of the hydraulic pump (4) by means of which the target trajectory (Δp) can be determined des，，filt ) And its time derivative->To obtain a control target value (i) of an adjusting device (22) of the hydraulic pump (4) P，des ) And by which the adjusting device can be actuated, characterized in that at least one load-dependent disturbance variable (q mot 、/>) Feeding the pre-control unit (32).
2. Hydraulic pump according to claim 1, wherein at least one load-dependent disturbance variable is a detected or ascertained pressure medium volume flow (q mot ) Or the time derivative of the volumetric flow of the pressure medium
3. Hydraulic pump according to claim 1 or 2, wherein the inverse model (42, 44, 46, 60) has a volume flow model (54), the output of which is a parameter (a) determining a target delivery volume of the hydraulic pump (4) P，soll )。
4. The hydraulic pump of claim 3 wherein the volumetric flow toThe inputs in the quantity model (54) are: at least one detected or determined delivery volume flow of the hydraulic pump (4) or a value (omega) on which this delivery volume flow is based P ) The target locus (Δp des，filt ) First order time derivative of (2)And the pressure medium volume flow (q) of the load (8) as a feedable load-dependent disturbance variable mot )。
5. The hydraulic pump according to any of the preceding claims, wherein the inverse model (42, 44, 46, 60) has a volume flow time derivative model (56), the output of which is a parameter (a) determining a target delivery volume of the hydraulic pump (4) P，soll ) Time derivative of (2)
6. The hydraulic pump of claim 5, wherein the input into the volumetric flow time derivative model (56) is: at least one detected or determined delivery volume flow of the hydraulic pump (4) or a value (omega) on which this delivery volume flow is based P ) The target locus (Δp des，filt ) First order time derivative of (2)Depending on the target trajectory (Δp des，filt ) Second time derivative>And the pressure medium volume flow (q) of the load (8) as a feedable load-dependent disturbance variable mot ) Time derivative of>
7. The hydraulic pump of any of the preceding claims, wherein the inverse model (42, 44, 46, 60) contains a leakage model (58), the inputs of which are: the target trajectory (Δp des，filt ) And a first time derivative of the target trajectoryAnd the output of the leakage model is: volumetric flow rate of leakage pressure medium (q leck ) And the time derivative of the volumetric flow of said leakage pressure medium +.>
8. Hydraulic pump according to claims 3 and 7, wherein the further input of the volume flow model (54) is the leakage pressure medium volume flow (q leck )。
9. Hydraulic pump according to claims 5 and 7, wherein the further input of the volumetric flow time derivative model (56) is the leakage pressure medium volumetric flow (q leck ) Time derivative of (2)
10. Hydraulic pump according to one of the preceding claims, having a regulating device (34) by means of which the pressure (Δp) and the required pressure (Δp) can be reduced des ) Is a deviation of (2).
11. The hydraulic pump according to claim 10, having a first comparison mechanism (38) by means of which the target trajectory (Δp des，filt ) The first is determined as a reduced number and the pressure (Δp) is taken as a reduced number-a difference value, wherein the first difference value is an input into the adjustment device (34).
12. The hydraulic pump according to claims 6 and 10, having a second comparison mechanism (40), the input of which is: as a subtracted number the target trajectory (Δp des，filt ) Is the second time derivative of (2)And an output of the adjustment device (34) as a reduction, wherein the output of the second comparison means (40) is a correlated trajectory.
13. Hydraulic pump according to any of the preceding claims, wherein the adjusting device (22) has a hydraulic actuator and a controllable current (i des ) To be actuated, a pressure medium volume (q stell ) And adjusting the pressure (p) x ) To load the actuator.
14. A hydraulic pump according to claim 3, wherein the inverse model (42, 44, 46, 60) comprises a characteristic curve (42) of the hydraulic pump (4), from which characteristic curve the rotational speed (ω) of the hydraulic pump (4) is dependent P ) The target locus (Δp des，filt ) And determining a parameter (alpha) of a target delivery volume of the hydraulic pump P，soll ) Can calculate the target adjustment pressure (p x，soll )。
15. The hydraulic pump according to claims 5 and 13, wherein the inverse model (42, 44, 46, 60) comprises a model (44) of the actuator by means of which at least the parameter (a) determining the target delivery volume is dependent on P，soll ) Time derivative of (2)Can determine the target regulated pressure medium volume (q stell，soll )。
16. A hydrostatic drive, comprising:
-at least one hydrostatic load (8) which can be coupled to an output device (6) of the drive device (1); and
hydraulic pump (4) designed according to any one of the preceding claims, which is fluidly connected to the load (8) in a hydraulic circuit and can be coupled to a drive machine (2) of the drive device (1).
CN202180084417.9A 2020-12-14 2021-07-27 Hydraulic pump for hydrostatic drive and hydrostatic drive Pending CN116583687A (en)

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DE102020215820.7A DE102020215820A1 (en) 2020-12-14 2020-12-14 Hydraulic pump for a hydrostatic drive, and hydrostatic drive
DE102020215820.7 2020-12-14
PCT/EP2021/071006 WO2022128180A1 (en) 2020-12-14 2021-07-27 Hydraulic pump for a hydrostatic drive, and hydrostatic drive

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* Cited by examiner, † Cited by third party
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DE19513032C1 (en) * 1995-04-06 1996-08-14 Brueninghaus Hydromatik Gmbh Supply volume setting device for hydraulic pump
DE19943336A1 (en) 1999-09-10 2001-04-05 Zahnradfabrik Friedrichshafen Conversion ratio regulation/rev regulation method for automobile automatic gearbox has non-linear compensation element corresponding to inverse model of variator path incorporated in regulation circuit
DE19943334A1 (en) 1999-09-10 2001-06-07 Zahnradfabrik Friedrichshafen Method for regulating a clutch or a brake in a transmission
DE102010021000A1 (en) 2010-05-12 2011-11-17 Getrag Getriebe- Und Zahnradfabrik Hermann Hagenmeyer Gmbh & Cie Kg Method for controlling a friction clutch
DE102012020632A1 (en) * 2012-10-19 2014-04-24 Robert Bosch Gmbh Method for driving hydraulic machine with variable displacement volume, involves reading reference value for displacement volume by using desired torque or desired volumetric flow rate at interface of hydraulic machine
EP2639657B1 (en) 2013-04-24 2018-04-04 MOOG GmbH Recording of an auxiliary variable in a way with minimum delay
DE102014224337B4 (en) 2014-11-28 2023-05-04 Robert Bosch Gmbh Method of controlling a hydrostatic drive
DE102016218197A1 (en) * 2016-09-22 2018-03-22 Robert Bosch Gmbh Hydrostatic slewing gear drive and method for controlling the hydrostatic slewing gear drive
DE102016222732A1 (en) 2016-11-18 2018-05-24 Robert Bosch Gmbh Method and device for performing a position control for a positioner unit

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