EP1097500A2 - Systeme de commande a groupe moteur integre - Google Patents

Systeme de commande a groupe moteur integre

Info

Publication number
EP1097500A2
EP1097500A2 EP99965714A EP99965714A EP1097500A2 EP 1097500 A2 EP1097500 A2 EP 1097500A2 EP 99965714 A EP99965714 A EP 99965714A EP 99965714 A EP99965714 A EP 99965714A EP 1097500 A2 EP1097500 A2 EP 1097500A2
Authority
EP
European Patent Office
Prior art keywords
control system
actuator
pump
signal
motor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP99965714A
Other languages
German (de)
English (en)
Other versions
EP1097500A4 (fr
Inventor
Steven B. Croke
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Lucas Aerospace Power Transmission Corp
Original Assignee
Lucas Aerospace Power Transmission Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Lucas Aerospace Power Transmission Corp filed Critical Lucas Aerospace Power Transmission Corp
Publication of EP1097500A2 publication Critical patent/EP1097500A2/fr
Publication of EP1097500A4 publication Critical patent/EP1097500A4/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B9/00—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member
    • F15B9/02—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type
    • F15B9/04—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type controlled by varying the output of a pump with variable capacity
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/18—Combined units comprising both motor and pump
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
    • F15B1/26—Supply reservoir or sump assemblies
    • F15B1/265—Supply reservoir or sump assemblies with pressurised main reservoir

Definitions

  • This invention relates to a control system for controlling position of an object.
  • the control system includes an integrated actuation package utilizing an electric motor driven servopump to control actuator position, and is useful for applications such as primary flight control.
  • an electric- based power distribution system in place of a hydraulic-based system.
  • replacement of the conventional aircraft hydraulic power distribution system with an electric power distribution system offers the potential for increased aircraft reliability, maintainability, efficiency and reduced aircraft weight and manufacturing cost.
  • a first type of actuation system that uses direct electric power for actuation is often referred to as an electrohydrostatic actuator (EH A).
  • a second type is often referred to as an electromechanical actuator (EMA).
  • EHA A electrohydrostatic actuator
  • EMA electromechanical actuator
  • both of these systems employ servomotor systems that control motor rotation, i.e., motor speed and direction, to position a linear actuator.
  • the main difference between the EHA and EMA systems is the specific manner in which energy is converted.
  • the EHA transforms rotary energy produced by an electric motor, for example a DC motor, to linear actuator energy via a hydraulic medium charged by a fixed displacement pump.
  • the EMA employs mechanical means, such as gears and ball screw actuator, to accomplish the energy conversion. It will be appreciated that both of these systems rely on changes of motor speed and direction, and it is thus often desirable to reduce rotational inertia that contributes to wear and more frequent maintenance of the system and its components.
  • IAP integrated actuation package
  • integrated actuation package denotes a servopump system where control of hydraulic pump displacement, i.e., control of hydraulic flow rate and flow direction, is used to position a linear actuator.
  • an IAP system is comprised of four primary elements: an electric motor; a hydraulic servopump; a linear hydraulic actuator; and a control system capable of translating actuator command and actuator position signals to a position error signal.
  • such a servopump actuation system employs a fixed speed, unidirectional motor powered by an electrical source, such as a conventional aircraft electric power source.
  • Actuator position control is accomplished by varying the hydraulic pump output flow rate and flow direction. This action is performed by changing the displacement of the servopump, as opposed to changing the rotational speed and direction of the servopump/electric motor system as in the EHA type systems.
  • An existing type of IAP system employs a swashplate powered by a fixed displacement boost pump.
  • a relief valve maintains a constant discharge pressure.
  • Fluid from the pump flows to an electrohydrauhc servovalve (EHSV), which positions a torque motor in response to an electric signal, moving a spool and sleeve to provide control flow to stroke control systems.
  • EHSV electrohydrauhc servovalve
  • These stroke control pistons provide the necessary force to move the swashplate to the desired position.
  • a feedback wire may also be incorporated into the servovalve to provide swashplate position feedback information directly to the EHSN.
  • An example of this system is shown in Figures la and lb, and an example is also described in Acee et al., Society of Aerospace Engineers (SAE) Technical Paper No. 920968, 1992, the disclosure of which is incorporated herein by reference.
  • System elements such as the boost pump, relief valve, EHSV and stroke control pistons, that are employed in existing IAP control system configurations, can be eliminated, thereby reducing the system weight. Additionally, this permits a lower steady state power draw, thereby resulting in reduced heat generation.
  • a first embodiment of this invention relates to a control system for controlling position of an object, that comprises: an object actuator for connection to the object to adjust its position, said actuator being activated by a variable displacement pump; a source for generating a position command signal; and a controller that receives the position command signal and an object actuator position signal, and translates the position command signal and the actuator position signal to generate a pump control signal.
  • the controller is in electrical connection with the variable displacement pump, such that the control signal effects change in displacement of the pump.
  • the pump is driven by an electric motor that operates at a constant direction to drive the variable displacement pump, and the electric motor includes a flywheel to increase rotational inertia thereof, thereby moderating peak power loads.
  • this invention relates to a control system for controlling position of an object, that comprises: an object actuator for connection to the object to adjust its position, said object actuator activated by a variable displacement pump; a source for generating a position command signal; and a controller that receives the position command signal and an actuator position signal, and translates the position command signal and the actuator position to generate a control signal.
  • the pump includes a variable angle swashplate that controls flow direction and flow rate of hydraulic fluid therein, and a rotary electrical actuator that adjusts the swashplate to a desired angular position in response to the control signal.
  • the rotary electrical actuator for the swashplate may include a rotational measurement device for measurement of rotational position of this actuator, and generates a rotary actuator position signal.
  • This rotary actuator position feedback signal is received at the controller, wherein the controller includes a closed loop that sums the object actuator position and position command signals, and compares the summed signals with the rotary actuator position signal, to generate the control signal for the rotary actuator.
  • Figure la and lb illustrate a prior IAP control system.
  • Figure 2 is a block diagram of an embodiment of a control system of this invention.
  • Figure 3 is a schematic perspective view of a control system according to various embodiments of this invention.
  • Figure 4 is a schematic view of a cooling fan for the system of Figure 3.
  • FIG. 5 is a perspective view of a IAP control system of this invention. Detailed Description of the Preferred Embodiment
  • Figures la and lb illustrate a prior IAP system.
  • the system includes an electrical motor 2, a hydraulic servopump 3 which, in this example, is a constant discharge variable displacement piston pump including pistons 6, a linear hydraulic actuator 4, and a controller 5 capable of translating actuator command and actuator position signals, to a position error signal.
  • Actuator 4 includes a hydraulic cylinder 22 and a linear variable displacement transducer (LVDT) 21; second actuator 4' is designed for incorporation in a second identical channel (not shown in Figure la).
  • Pump 3 is shown in more detail in Figure lb.
  • a swashplate 7 is powered by a fixed displacement boost pump 8.
  • a boost relief valve 9 maintains a constant discharge pressure, and fluid from the boost pump flows to an electrohydraulic servovalve (EHSV) 10, which positions a torque motor in response to an electric signal, providing control flow to stroke control systems.
  • EHSV electrohydraulic servovalve
  • stroke control pistons 12 provide force to move the swashplate 7 to the desired position.
  • a feedback wire 13 provides swashplate position information to the EHSV 10.
  • the system further includes: a bootstrap accumulator 15 which uses boost pump pressure to maintain pump inlet pressure; a pressure switch 16 which monitors boost output pressure to alert the controller of pump or motor failure; a shuttle valve 17 which provides make-up flow for any piston pump leakage; relief valves 18 which limits maximum system pressure; a solenoid by-pass valve 19 which is commanded and powered by the controller 5 to allow the system to have free-flow between actuator chambers during a system failure; and a filter 20.
  • a bootstrap accumulator 15 which uses boost pump pressure to maintain pump inlet pressure
  • a pressure switch 16 which monitors boost output pressure to alert the controller of pump or motor failure
  • a shuttle valve 17 which provides make-up flow for any piston pump leakage
  • relief valves 18 which limits maximum system pressure
  • a solenoid by-pass valve 19 which is commanded and powered by the controller 5 to allow the system to have free-flow between actuator chambers during a system failure
  • a filter 20 Such IAP control systems employ the parameter of actuator position as the controlled parameter.
  • the position command signal is summed with the object actuator position feedback signal to produce a position error signal (or pump control signal) received at servo valve 10.
  • the position error signal may be compared with a swashplate position signal (from feedback wire 13).
  • FIG 2 is a schematic illustration of a control system according to various embodiments of this invention. Similar to the IAP control system of Figure la, this system employs the parameter of object actuator position as the controlled parameter, where the system includes a servopump 3 used to power the actuator 4 for connection to the objection whose position is controlled.
  • pump 3 is a variable displacement piston pump that provides servo control of the actuator 4 by varying the displacement and direction of the piston pump flow. This is accomplished by rotating the swashplate 7 in either of two directions from a plane perpendicular to the rotation of the pump.
  • the system of Figure 2 includes an electrically driven actuator 30 in connection with the swashplate 7 of pump 3.
  • the rotary electrical actuator 30 adjusts the swashplate to a desired angular position.
  • controller 5 sums the position command signal from position command source 11 and the actuator position feed back signal from the LVDT 21 in connection with linear actuator 4, to general the control signal to actuator 30.
  • actuator 30 includes a rotary variable displacement transducer (RVDT) position transducer 31 , that serves as a rotational measurement device to detect the rotational position of actuator 30 and provide enhanced system control.
  • Transducer 31 is in electrical connection with controller 5, such that controller 5 receives a tilt block position feedback signal indicative of the rotary actuator position.
  • Controller 5 sums the position command 5 signal from position command source 11 and the object actuator position signal from the LVDT 21, and compares the summed signals with the rotary actuator position feedback signal to general the control signal to actuator 30.
  • Actuator 30 may have the form of a bidirectional electric motor, reduced speed gearbox with the RVDT 0 position transducer 31 embedded therein.
  • motor 2 may be an AC induction motor, such as a 115 VAC constant speed electric motor as commonly 0 employed in aircraft systems. For aircraft applications, this avoids the need to modify existing electric power generating systems. For applications that lack AC electrical power, the servopump system can be driven by a fixed speed DC motor.
  • a solenoid by-pass valve 19 may be provided in electrical 5 connection with controller 5, to allow the system to have free-flow between actuator chambers during a system failure.
  • the system of Figure 2 may further include the shuttle valve 17 to provide make-up flow for any piston pump leakage, and relief valves 18 to limit maximum system pressure.
  • a bootstrap accumulator 15 may be 0 employed in the system of Figure 2 to maintain pump inlet pressure; since this system does not employ a boost pump, accumulator 15 may be gas-charged. Also, the system of Figure 2 may include a second actuator 4', as in the system of Figure la, designed for incorporation in a second identical channel (not shown in Figure 2).
  • FIG. 3 illustrates schematically a single channel of an IAP control system according to an additional embodiment of this invention.
  • motor 2 is provided with increased rotational inertia.
  • IAP-type control systems include a constant speed and direction electric motor 2 that drives the variable displacement servopump 3.
  • Control of actuator 4 is accomplished through varying the displacement of the servopump 3 and without changing direction or speed of the rotation of the motor and pump.
  • Systems of this type differ from various prior alternate EHA or EMA configurations in that the rotating motor and pump do not need to be accelerated and decelerated in opposite directions during actuation control. Accordingly, whereas a design goal of such prior configurations is to minimize rotating inertia, so as to minimize wear and maintenance of the system and its components, this embodiment of the present advantage takes advantage of increased inertia.
  • additional mass is incorporated in the rotating pump and motor assembly. This is preferably accomplished by adding mass near the outer radius of the rotating assembly, thereby increasing inertia with minimal overall weight increases to the system.
  • this increased mass can be incorporated in a cooling fan, as the motor will typically include such a cooling fan mounted to the outboard side of the system.
  • the cooling fan acts as a flywheel to increase rotational inertia. This is illustrated schematically in Figure 4 where cooling fan 32 has increased mass 33 about its periphery to augment rotational inertia.
  • an application may require a constant load of about 4 to 5 horsepower with peak loads of short duration of about 15- 20 hp (i.e., peak loads occur when changing the position of the actuator).
  • peak loads typically, an electrical motor with a maximum output of 20 hp would be employed to meet the system demands.
  • a lower rated motor for example, a motor with a maximum output of 5 hp, may be employed, that is still able to meet system demands for the short, intermittent peak loads.
  • This embodiment of the invention may be incorporated in the system of Figure la, or preferably in the system of Figure 2.
  • FIG. 5 A preferred configuration of an overall control system is illustrated in Figure 5.
  • This system is a dual-channel actuation system, including a first channel 40 including actuator 4, electrical motor 2 and pump 3, and a second channel 40' including actuator 4', motor 2' and pump 3', mounted to manifold blocks 42, 42'.
  • Each channel includes an electrical connector 44, 44' for connecting the electrical motor to a power source (for example, an aircraft power source), and an electrical connector 45, 45' for connecting the system to the controller 5 ( Figure 2).
  • Each motor 2 includes a flywheel 33, 33' on its cooling fan for providing increased inertia mass.
  • Each channel includes a rotary actuator 30, 30' to drive the swashplates of the pump 3,3', respectively , including RVDT position transducers 31, 31 ' and electrical connectors for connection to the controller.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Servomotors (AREA)
  • Control Of Position Or Direction (AREA)
  • Reciprocating Pumps (AREA)

Abstract

L'invention porte sur un système de commande de la position d'un objet consistant en groupe moteur intégré comportant une servopompe, entraînée par un moteur électrique, commandant la position d'un vérin de commande. Le moteur électrique, à sens de rotation et régime constant, présente une forte inertie, tandis que la position du plateau oscillant de la servopompe à cylindrée variable se règle directement au moyen d'un actionneur électrique rotatif.
EP99965714A 1998-07-15 1999-07-13 Systeme de commande a groupe moteur integre Withdrawn EP1097500A4 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US9294298P 1998-07-15 1998-07-15
US92942P 1998-07-15
PCT/US1999/015880 WO2000016464A2 (fr) 1998-07-15 1999-07-13 Systeme de commande a groupe moteur integre

Publications (2)

Publication Number Publication Date
EP1097500A2 true EP1097500A2 (fr) 2001-05-09
EP1097500A4 EP1097500A4 (fr) 2003-05-02

Family

ID=22235891

Family Applications (1)

Application Number Title Priority Date Filing Date
EP99965714A Withdrawn EP1097500A4 (fr) 1998-07-15 1999-07-13 Systeme de commande a groupe moteur integre

Country Status (3)

Country Link
EP (1) EP1097500A4 (fr)
JP (1) JP2002525515A (fr)
WO (1) WO2000016464A2 (fr)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB0120747D0 (en) * 2001-08-25 2001-10-17 Lucas Western Inc Control method
US7249458B2 (en) * 2005-07-22 2007-07-31 Ashradn Holdings Ltd. Self-contained hydraulic actuator system
GB2469016A (en) * 2009-02-26 2010-10-06 Ge Aviat Systems Ltd Electrically driven hydraulic actuator
JP5666233B2 (ja) * 2010-10-08 2015-02-12 ナブテスコ株式会社 航空機アクチュエータの油圧装置
JP5453356B2 (ja) * 2011-07-07 2014-03-26 株式会社堀内機械 液圧装置および液圧装置の制御方法
US8517040B2 (en) * 2011-08-12 2013-08-27 Hamilton Sundstrand Corporation Valve control of pump inlet pressure with bootstrap reservoir
WO2013112181A1 (fr) * 2012-01-27 2013-08-01 Kavlico Corporation Système de détection d'un transformateur différentiel variable rotatif (rvdt) pourvu d'un signal de sortie auxiliaire
BE1024061B9 (nl) * 2016-04-12 2018-01-23 Atlas Copco Airpower Nv Werkwijze voor het beschermen van elektrische motoren van compressoren met een continu capaciteitregelsysteem.
WO2017177287A2 (fr) 2016-04-12 2017-10-19 Atlas Copco Airpower, Naamloze Vennootschap Procédé de protection d'un moteur électrique d'un dispositif avec un consommateur motorisé doté d'un système de commande de capacité continue et choix d'un tel moteur
US11118610B2 (en) * 2017-08-29 2021-09-14 The Boeing Company Low profile electro-hydrostatic actuator
US11994117B2 (en) * 2021-10-04 2024-05-28 Hamilton Sundstrand Corporation Variable positive displacement pump actuator systems

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3646754A (en) * 1970-05-22 1972-03-07 Ltv Electrosystems Inc Motor operated servo pump
US3902318A (en) * 1974-08-28 1975-09-02 Sperry Rand Corp Power transmission
US4587808A (en) * 1981-03-30 1986-05-13 Hitachi Construction Machinery Co., Ltd. Control system for hydraulic circuit means
EP0271744A2 (fr) * 1986-11-24 1988-06-22 Liebherr-Aero-Technik GmbH Actuateur electro-hydraulique
EP0413463A1 (fr) * 1989-08-12 1991-02-20 Lucas Industries Public Limited Company Dispositif d'entraînement des surfaces de commande d'un aéronef

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Publication number Priority date Publication date Assignee Title
US3906266A (en) * 1974-02-22 1975-09-16 Black & Decker Mfg Co High inertia insulating cooling fan for electric motor device
DE3716200C2 (de) * 1987-05-14 1997-08-28 Linde Ag Steuer- und Regeleinrichtung für ein hydrostatisches Antriebsaggregat und Verfahren zum Betreiben eines solchen
US5666806A (en) * 1995-07-05 1997-09-16 Caterpillar Inc. Control system for a hydraulic cylinder and method

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3646754A (en) * 1970-05-22 1972-03-07 Ltv Electrosystems Inc Motor operated servo pump
US3902318A (en) * 1974-08-28 1975-09-02 Sperry Rand Corp Power transmission
US4587808A (en) * 1981-03-30 1986-05-13 Hitachi Construction Machinery Co., Ltd. Control system for hydraulic circuit means
EP0271744A2 (fr) * 1986-11-24 1988-06-22 Liebherr-Aero-Technik GmbH Actuateur electro-hydraulique
EP0413463A1 (fr) * 1989-08-12 1991-02-20 Lucas Industries Public Limited Company Dispositif d'entraînement des surfaces de commande d'un aéronef

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO0016464A2 *

Also Published As

Publication number Publication date
WO2000016464A2 (fr) 2000-03-23
JP2002525515A (ja) 2002-08-13
WO2000016464A9 (fr) 2001-07-05
WO2000016464A3 (fr) 2000-07-13
EP1097500A4 (fr) 2003-05-02

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