Search

CN-116583687-B - Hydraulic pump for hydrostatic drive and hydrostatic drive

CN116583687BCN 116583687 BCN116583687 BCN 116583687BCN-116583687-B

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.

Inventors

  • S. Muci le
  • M. HIRSCH
  • A. Trazite

Assignees

  • 罗伯特·博世有限公司

Dates

Publication Date
20260512
Application Date
20210727
Priority Date
20201214

Claims (16)

  1. 1. Hydraulic pump with adjustable delivery volume for pressure-controlled supply of a hydrostatic load (8), comprising a path planning unit (30) by means of which a desired pressure of the hydraulic pump (4) can be achieved ) For the target track with flatness ) And the time derivative of the target track 、 ) Planning and being able to be transmitted to a pre-control unit (32) of the hydraulic pump (4), said pre-control unit comprising at least an inverse model (42, 44, 46, 60) of the hydraulic pump (4) by means of which it is possible to calculate the target trajectory # ) And its time derivative 、 ) To obtain the control target value of the adjusting device (22) of the hydraulic pump (4) ) And the control device can be operated by the control device, which is characterized in that at least one interference parameter which depends on the load is # 、 ) Feeding the pre-control unit (32).
  2. 2. Hydraulic pump according to claim 1, wherein at least one load-dependent disturbance variable is the detected or determined pressure medium volume flow of the load (8) ) Or the time derivative of the volume flow of the pressure medium )。
  3. 3. The hydraulic pump according to claim 1 or 2, wherein the inverse model (42, 44, 46, 60) has a volumetric flow model (54), the output of which is a parameter ± determining a target delivery volume of the hydraulic pump (4) )。
  4. 4. A hydraulic pump according to claim 3, wherein the input into the volume flow model (54) is at least one detected or calculated delivery volume flow of the hydraulic pump (4) or a value based on this delivery volume flow # ) The target track ) First order time derivative of ) And the volumetric flow of the pressure medium of the load (8) as a feedable load-dependent disturbance variable )。
  5. 5. A hydraulic pump according to claim 3, wherein the inverse model (42, 44, 46, 60) has a volumetric flow time derivative model (56), the output of which is a parameter ± determining a target delivery volume of the hydraulic pump (4) ) Time derivative of [ (] )。
  6. 6. The hydraulic pump according to claim 5, wherein the input into the volumetric flow time derivative model (56) is at least one detected or calculated delivery volumetric flow of the hydraulic pump (4) or a value based on this delivery volumetric flow # ) The target track ) First order time derivative of ) Depending on the target track ) Second time derivative of [ ] ) As well as the pressure medium volume flow of the load (8) as a feedable load-dependent disturbance variable ) Time derivative of [ (] )。
  7. 7. The hydraulic pump of claim 5, wherein the inverse model (42, 44, 46, 60) includes a leakage model (58) having an input of the target trajectory # ) And the first time derivative of the target track ) And the output of the leakage model is that the volume flow of the leakage pressure medium is [ ] ) And the time derivative of the volume flow of the leakage pressure medium )。
  8. 8. The hydraulic pump of claim 7, wherein the further input of the volumetric flow model (54) is the leakage pressure medium volumetric flow ± )。
  9. 9. The hydraulic pump of claim 7, wherein the further input of the volumetric flow time derivative model (56) is the leakage pressure medium volumetric flow ± ) Time derivative of [ (] )。
  10. 10. Hydraulic pump according to claim 1 or 2, having an adjusting device (34) by means of which the pressure can be reduced ) Is equal to the required pressure ) Is a deviation of (2).
  11. 11. The hydraulic pump according to claim 10, having a first comparison means (38) by means of which the target trajectory ± ) As reduced numbers and at said pressure ) The first difference is determined as a reduction, wherein the first difference is an input to the control device (34).
  12. 12. The hydraulic pump according to claim 10, having a second comparison means (40) with an input of the target trajectory as a reduced number # ) Second time derivative of [ ] ) 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. 13. A hydraulic pump according to claim 3, wherein the adjusting device (22) has a hydraulic actuator and a controllable current ) The hydraulic valve is controlled, and the volume of the pressure medium can be regulated according to the control of the hydraulic valve ) And adjust the pressure ) To load the actuator.
  14. 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 of the hydraulic pump (4) is dependent ) The target track ) Determining a parameter of a target delivery volume of the hydraulic pump ) Can calculate the target regulating pressure )。
  15. 15. The hydraulic pump of claim 13, wherein the inverse model (42, 44, 46, 60) comprises a model (44) of the actuator by which at least a parameter @ that determines the target delivery volume is dependent on ) Time derivative of [ (] ) Can calculate the volume of the pressure medium of the target adjustment )。
  16. 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).

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. A travel drive of this type is shown in the applicant's publication DE 102014224337 A1. 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 (hereinafter hydraulic pump), which can be operated as a hydraulic pump and can be coupled to the drive machine, 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. The target trajectory featuring Flatness (FLACHHEIT) and its time derivative can be planned for the required pressure by means of the device. 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