WO1999063232A1 - Systeme de positionnement de servocommande - Google Patents

Systeme de positionnement de servocommande Download PDF

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Publication number
WO1999063232A1
WO1999063232A1 PCT/US1998/011736 US9811736W WO9963232A1 WO 1999063232 A1 WO1999063232 A1 WO 1999063232A1 US 9811736 W US9811736 W US 9811736W WO 9963232 A1 WO9963232 A1 WO 9963232A1
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WO
WIPO (PCT)
Prior art keywords
armature
gap
signal
output signal
valve
Prior art date
Application number
PCT/US1998/011736
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English (en)
Inventor
J. Otto Byers
Lambert Haner
Original Assignee
J. Otto Byers & Associates
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Publication date
Application filed by J. Otto Byers & Associates filed Critical J. Otto Byers & Associates
Priority to PCT/US1998/011736 priority Critical patent/WO1999063232A1/fr
Publication of WO1999063232A1 publication Critical patent/WO1999063232A1/fr

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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
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • F15B11/04—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed
    • F15B11/05—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed specially adapted to maintain constant speed, e.g. pressure-compensated, load-responsive
    • 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
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F15B13/044—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by electrically-controlled means, e.g. solenoids, torque-motors

Definitions

  • This invention relates to a positioning system for an electro-hydraulic servo with specific but not limited application to a valve.
  • the system includes a force motor with magnetic coils which position the valve in response to a command signal to accomplish a desired flow rate, Hall effect sensors which sense the actual valve position and/or flow rate, and a control circuit which re-positions the valve in response to the sensed position.
  • Typical hydraulic systems utilize large force electromagnetic drivers to position directional control valve spools.
  • electrically actuated valves usually have two solenoids, one positioned on either side of the valve, to provide actuation of the spool in two directions.
  • Some applications cause the spool to move between three positions — center, flow to control port A or flow to control port B.
  • Some applications allow for flow proportional to the current applied to the solenoids by causing the solenoid force which is related to current level to act against a spring.
  • Some applications have position feedback and electronic control for spool position which is generally provided by an LVDT to cause the spool to move to precise positions that match precise command signals.
  • valves of this type it is advantageous for valves of this type to actually control flow rate, regardless of pressure drop across the main stage valve spool.
  • Byers in patent 3,561,488 provided a means to do this in a two stage proportional valve.
  • This patent provides a single stage single rectilinear force motor driven proportional valve or servo-valve with high gain where the working flux density from a permanent magnet that is required to make the valve bi-directional is sensed to provide the spool position. It also provides a way to compensate for the flow variation caused by changes in pressure drop across the valve spool in a single stage proportional and/or servo valve.
  • the rectilinear force motor provides sufficient force and travel to control the positions of a single stage proportional and/or servo valve such that the four- way valve spool is positioned for direction and degree of opening proportional to the command voltage or current, or in one version the spool is positioned to a variable position which corrects for the error caused by varying pressure drop across the spool.
  • the feedback for the single stage valve is provided by measuring the flux density in the two working flux paths with flux density sensors, summing the output of the sensors, then combining the combined signal with a command signal that may be modified by a signal that is proportional to the voltage or current flow rate and direction of the working current through the force motor.
  • the result is a more compact, less expensive, more accurate, single stage servo valve.
  • the valve also may provide higher force levels which eliminates the contamination problems associated with most proportional and servo valves both single stage and multiple stage.
  • Figure 1 is a longitudinal sectional view of the positioning system of the present invention shown in conjunction with a valve;
  • Figure 2 is a schematic diagram of the control circuit of the present invention with current feedback;
  • Figure 2a is a schematic diagram similar to Figure 2 depicting another embodiment of the current feedback circuitry
  • Figure 3 is a longitudinal sectional view of the positioning system maintaining a valve in an operational position (also shows magnetic circuits);
  • Figure 4 is a longitudinal sectional view of another embodiment of the positioning system of the present invention shown in conjunction with a valve;
  • Figure 5 is a schematic diagram of the control circuit similar to that shown in Figure 2, but without current feedback
  • Figure 6 is a graph showing the relationship between armature and spool position and command signal at minimum and maximum current with a positioning system according to Figure 1 and control system according to Figure 2;
  • Figure 7 is a graph showing the relationship between armature and spool position and command signal at minimum and maximum current with a positioning system according to Figure 4 and control system according to Figure 2;
  • Figure 8 is a graph showing the relationship between armature and spool position and command signal at minimum and maximum current with a positioning system according to Figure 1 and control system according to Figure 5 ; and Figure 9 is a fragmented longitudinal section view of the force motor showing the magnetic circuits for both the permanent magnetic and electro-magnetic circuits generated by the coils.
  • FIG. 1 shows the present invention 10 in conjunction with a hydraulic valve assembly 12.
  • Valve assembly 12 may be used to control the flow of hydraulic fluid to a hydraulic motor, or a hydraulic cylinder.
  • the operation of valve assembly 12 is commonly known in the art as is evidenced by U.S. Patent No. 5,249,603 which is incorporated herein by reference.
  • valve 12 is enclosed within a housing 14 which includes an inlet port 16, cylinder port 18, cylinder port 69 and return port 72.
  • a spool is disposed within bore 20.
  • Spool 22 is moveable to the left and to the right. If it moves to the left, annulus 24 is connected across metering orifice 75 to annulus 74 and to cylinder port 18 to motor 76.
  • the return flow from the motor enters port 69, passes through annulus 67, across metering orifice 70 to annulus 71 and to return port 72. If the spool is moved to the right, annulus 24 is connected across metering orifice 23 to annulus 67 to cylinder port 69 to motor 76, and back into port 18.
  • the design of the force motor 26 and electronic circuit per Figure 2 are such that the spool 22 can be commanded to stay in any commanded position from center to any opening to port A or to any opening to port B, or to pass any flow rate to port A or B regardless of pressure drop (i.e. the pressure differential between port A and port B) across the spool within broad tolerances.
  • Plug 77 seals the left end on bore 20.
  • Drive rod 34 is connected by universal joint 73 to spool 22 in a manner that allows drive rod 34 to move spool 22 in either direction freely even if the bore is not in perfect alignment with the drive rod 34.
  • the drive forces for the spool 22 are the magnetic forces in air gaps 42 and 44 between moveable armature 28 and pole pieces 166 and 168 or by centering spring assembly 40 through rod 38.
  • drive rod 34 moves spool 22 within valve bore 20 so that either flow passes across metering orifice 75 to port A and from port 69 across metering orifice 70 to return port 72, or passes across metering orifice 23 to port 69 and from port 18 across metering orifice 25 to the return port 72.
  • linear force motor 26 includes an armature 28 situated within a cavity 30 defined by tube 77.
  • Armature 28 has a forward side 32 connected by drive rod 34 to spool 22, and a rearward side 36 connected by support rod 38 to spring assembly 40 which biases armature 28 to a central position within cavity 30.
  • Forward side 32 of armature 28 forms a forward gap 42 with forward pole piece 168
  • rearward side 36 forms a rearward gap 44 with rearward pole piece 166.
  • Armature 28 is freely movable rectilinearly within cavity 30 along an axis 46 defined by rods 34,38. Also, as armature 28 moves along axis 46, forward gap 42 and rearward gap 44 increase and decrease in direct, inverse relationship to one another as will be described in further detail below.
  • Permanent magnet 48 which has an annular shape with radial magnetization as noted by poles "N" and “S. " Permanent magnet 48 has an internal surface 50 which is closely spaced from an external surface 52 of armature 28. As is well known in the art, permanent magnet 48 can be fabricated in a single piece or multiple piece construction using one of various types of permanent magnetic materials. The dimensions of permanent magnet 48 depend upon the desired output force of motor 26 and material selected.
  • First and second electro-magnetic coils 54,56 are of annular shape and positioned on opposite ends of permanent magnet 48. Coils 54,56 are each wound on a non-magnetic core (not shown) of substantial tubular shape. First coil 54 is electrically connected to second coil 56 generally in a series circuit.
  • a first Hall effect sensor 58 is disposed directly adjacent first coil 54 within outer housing 81 to measure the flux 62 associated with forward gap 42.
  • a second Hall effect sensor 60 is disposed directly adjacent second coil 56 within outer housing 81 to measure the flux 64 associated with rearward gap 44.
  • Sensors 58,60 which are commercially available, generate electricity in response to magnetic flux. The manner in which sensors 58,60 provide flux measurements is well known in the art and does not constitute a part of the present invention. As shown in Figures 3 and 9, flux generated by the permanent magnet and coils flows around coils 54,56 and passes through sensors 58,60. This causes sensors 58,60 to generate respective electrical voltages which are proportional to the magnitude and direction of the magnetic flux density passing through the sensors.
  • First sensor 58 produces a voltage on output line 102 (shown in Figure 2) which corresponds to measured flux 62.
  • second sensor 60 produces a voltage on output line 104 (shown in Figure 2) which corresponds to measured flux 64.
  • the polarities of the voltages on lines 102,104 depend upon the direction of flow of flux currents 62, 64, 82, 83, 84 and 85.
  • a typical commercially available Hall effect sensor also provides an integral amplification stage that increases the voltage output of the sensor to a usable level. This voltage is above or below a baseline voltage depending on the direction of flux flow.
  • the sensor outputs on lines 102,104 have opposite polarities from the baseline by arrangement and provide a measure of armature 28 position when processed by control circuit 100 as described in detail below.
  • Hall sensors 58,60 are each connected between supply voltage 106 and ground 108.
  • output line 102 is connected to the positive input of driver 110, and output line 104 is connected to the positive input of driver 111.
  • the negative input of driver 110 is connected to resistor 112 and resistor 114.
  • the negative input of driver 111 is connected to resistor 112 and resistor 116.
  • Driver 110 output is connected to resistor 114 and resistor 118 which is connected to the negative input of difference amplifier 120.
  • Resistor 118 is also connected to resistor 122 which is connected to the output of difference amplifier 120.
  • Driver 111 output is similarly connected to resistor 116 and resistor 124 which is connected to the positive input of difference amplifier 120.
  • Resistor 124 is also connected to resistor 126 which is connected to ground 108.
  • the output of difference amplifier 120 i.e., the sum of the two inputs to the amplifier, is routed to resistor 128 which is connected to the summing junction 130 and the control amplifier 132.
  • a compensation network 134 is connected between summing junction
  • control amplifier 132 outputs The positive input to control amplifier 132 and control amplifier 132 output.
  • the positive input to control amplifier 132 is connected to ground 108.
  • the output of control amplifier 132 (the "Compensation" signal) is connected to the coil driver 136 which is, in turn, connected to first coil 54.
  • first coil 54 and second coil 56 are connected together in series.
  • Second coil 56 is also connected to resistor 138 and resistor 140.
  • Resistor 140 is connected to the negative input of the current compensation amplifier 144 and feedback resistor 142.
  • Resistor 138 is connected to ground 108.
  • the positive input of current compensation amplifier 144 is also connected to ground 108.
  • Resistor 142 is connected to resistor 146 at the output of current compensation amplifier 144.
  • a "Sensed Current” signal (V sc ) is produced on line 148 which is routed back to summing junction 130.
  • command block 150 which is shown as a commonly available potentiometer in Figure 2, provides a "Commanded Position” signal (V CP ) to summing junction 130.
  • Command block 150 is connected to positive supply voltage 106 on one end, negative supply voltage 107 on the other end, and wiper 152 in a variable voltage divider configuration commonly known to those skilled in the art.
  • Wiper 152 can be adjusted using various electrical or mechanical means. Wiper 152 provides the "Commanded Position" signal through resistor 154 on line 148 which is routed to summing junction 130.
  • An additional embodiment of the force motor of the present invention is shown in Figure 4.
  • the motor of Figure 4 has an armature 28 enclosed within a cavity 30.
  • the armature 28 shifts along an axis 46 defined by rods 34 and 38 connected to armature 28.
  • the forward side 32 of armature 28 forms a forward gap 42 with the forward pole piece 168 and the rearward side 36 forms a rearward gap 44 with the rearward pole piece 166.
  • the motor of Figure 4 has a single coil 160 which is closely spaced from the external surface 164 of armature 28.
  • Coil 160 has sufficient length to extend axially beyond forward gap 42 and rearward gap 44.
  • Two pole pieces 166 and 168 are disposed within outer housing 81 in proximity to the ends of coil 160.
  • a permanent magnet 162 surrounds coil 160.
  • the inner surface 170 of permanent magnet 162 mates with the outer surface 172 of coil 160.
  • Hall effect sensor 58 is positioned within pole piece 168 in operable association with gap 42.
  • Hall effect sensor 60 is positioned within pole piece 166 in operable association with gap 44.
  • this version is less efficient than Figure 1, but since all of the flux from the coil goes through both gaps, 42 and 44, the reluctance in the electromagnetic circuit 86 does not change with position of the armature, and the flux per ampere turn will also not change with armature position.
  • the relationship between the actual spool position and the command position for control loop according to Figure 2 and a motor per Figure 4 is shown in Figure 7.
  • Figure 5 shows control loop 200 for the force motor 26 of Figure 1 and force motor 89 of Figure 4.
  • the only difference between Figure 2 and Figure 5 is that the current feedback loop shown in Figure 2, items 138, 140, 142, 144 and 146 have been removed; therefore, the commanded position is not modified by the current flow through the coils.
  • the relationship between the actual spool position and the command position for a control loop according to Figure 2 and a motor per Figure 1 is shown in Figure 6.
  • Figures 6, 7, and 8 use the same coordinates and are intended to show the same relationships but with different motor and control system configurations.
  • the horizontal axis is armature and spool position in two directions from center. To the right of center is with a plus (+) command signal. To the left of center is with a minimum (-) command signal. The amount of spool movement from center varies as a function of current though the coils.
  • Each graph shows the relationship of armature and spool position and the control signal at minimum and maximum current.
  • Figure 6 is with current feedback that exactly compensates for error due to flux generated by current through the coils at the point that flow starts to a cylinder port.
  • the graph shows a small decrease in travel per unit command signal resulting in less spool travel per unit command at maximum current (Position B) as compared to at minimum current (Position A).
  • Figure 7 is with a motor according to Figure 4 and control according to Figure 2 with the only change in flux per unit command signal being due to the change in leakage at various positions. This error is very small.
  • Figure 8 shows a motor according to Figure 1 with a control system without current feedback or as shown in Figure 5. It shows a larger decrease (compared to Figure 6) in travel of the spool per unit command signal as the closing force due to flow force increases. As shown in the graph, this is very advantageous in a hydraulic flow control valve.
  • Figure 10 shows all of the flux flow paths in the motor per Figure 1. It is shown to explain the mathematical model.
  • F A Clockwise flux from P.M.
  • F H Total flux from coil 1
  • F L The part of flux from coil 2 that passes through gap 42.
  • F B CCW flux from P.M.
  • F G The part of flux from coil 1 that passes through gap 44
  • F j Total flux from coil 2.
  • Total permanent magnet flux: F ⁇ _ Am 6450
  • a m Area permanent magnet (P.M.),
  • R F Reluctance across P.M.
  • G F friction force (In proportional and servo valves, this is very small and can often be ignored)
  • G 2 magnetic force in larger gap
  • G M Net P.M. + E.M. , magnetic force.
  • Gs ( G ⁇ - G 2 ) + G F
  • Valve assembly 12 and motor 26 are assembled to ensure that when armature 28 is at magnetic center (i.e. positioned in the center of cavity 30 so that forward gap 42 is equal to rearward gap 44), spool 22 is at hydraulic center.
  • Spring assembly 40 biases or pre-loads armature 28 through support rod 38 to magnetic center with the drive rod 34 positioning spool 22 to hydraulic center.
  • the physical layout of permanent magnet 48 i.e., centered around armature 28 between first coil 54 and second coil 56 results in flux lines traveling around first coil 54 in a clockwise direction (illustrated by line 62) and around second coil 56 in a counterclockwise direction (illustrated by line 64).
  • the flux paths associated with the coils 54, 56 are in the same direction and add to the flux density from the permanent magnet in one gap and subtract in the other gap. With zero current through the coils, armature 28 will remain in the center position. If, however, armature 28 moves off center even slightly, for example toward forward gap 42, forward gap 42 decreases in width, the flux density associated with gap 42 becomes more positive, rearward gap 44 increases in width, and the flux density associated with gap 44 becomes less negative. Consequently, the natural tendency of armature 28 is to move off center and continue moving until stopped by pole piece 168. Thus, the force from spring assembly 40 biasing armature 28 toward center must be greater that the flux force generated by permanent magnet 48 at all armature positions.
  • second Hall effect sensor 60 provides a voltage on line 104 to driver 111 which represents the density and direction of flux around second coil 56.
  • the Hall sensors are arranged such that the signal polarities are opposite. Since drivers 110,111 are balanced, the inputs to difference amplifier 120 are opposite polarity and identical magnitude . These signals are combined by difference amplifier 120 to produce the "Sensed Position" signal at summing junction 130. In this example, since armature 28 is balanced at center and the sensor measurements at the inputs to difference amplifier 120 are equal in magnitude, the signals cancel and the "Sensed Position" signal is approximately zero volts.
  • Vsc sensed Position signal
  • coils 54,56 do not contribute to VSP because coils 54,56 are not energized by energizing current.
  • the closed-loop control circuit 100 simply permits armature 28 to remain in the center position under the biasing force of spring assembly 40.
  • Command block 150 is adjusted to provide a "Commanded Position” signal (VCP) to summing junction 130 which, according to a predetermined relationship between command block 150 voltage and spool 22 position, corresponds to the spool 22 position shown in Figure 3 (i.e., spool 22 is barely cracked opened).
  • VCP "Commanded Position” signal
  • This initial “Commanded Position” signal (V CP1 ) is routed to summing junction 130 where it is combined with the initial "Sensed Position” signal (V SP1 ) corresponding to the initial position of armature 28.
  • the initial “Sensed Current” signal (V SC1 ) is also combined with V CP1 .
  • V SP1 and V SC1 are both initially zero volts as described above, the "Compensation" signal at the output of current compensation amplifier 144 is directly proportional to V CP1 .
  • coil driver 136 produces energizing current. This current causes first and second coils 54, 56 to produce flux.
  • the direction of the energizing current in this example causes coils 54, 56 to produce flux 84, 85 in a clockwise direction as shown in Figure 3.
  • the flux due to coils 54, 56 i.e. , flux path 83 and 84, respectively
  • the combined permanent magnet and E.M. flux at gap 42 is measured by first Hall effect sensor 58.
  • the combined permanent magnet and E.M. flux at gap 44 is measured by Hall effect sensor 60.
  • the flux at gap 42 is the clockwise permanent magnet flux shown in Figure 1 plus the flux from both coils shown in Figure 3.
  • the flux at gap 44 is the counter clockwise permanent magnet flux shown in Figure 3 minus the flux from both coils shown in Figure 3.
  • the input signal from command block 150 (V CPI ) will be summed with sensed current voltage (V SC1 ) so that the command position voltage on line 160 will be modified by (V SC1 ), the exact voltage change as caused by flux density changes at sensors 58 and 60 generated by flux from coils 54 and 56 when measured as sensed position (V SP1 ) at summing junction 130.
  • command block 150 When a command signal is entered into command block 150 which is predetermined to position the spool at a point to just start flow to port 18, there will be a (+) plus voltage in line 160. Before the armature 28 starts to move, the outputs of sensors 58 and 60 will be equal and opposite. Therefore, the output of difference amplifier 120 at summing junction 130 will be (0) zero.
  • the (+) plus command voltage at junction 130 will cause a (+) plus voltage output from control amplifier 132 that is proportional to the input signal over a small range.
  • the output signal from amplifier 132 will cause the coil driver 136 to provide (+) plus voltage to coils 54 and 56 that is also proportional to the input signal from junction 130 over a small range.
  • the command signal to junction 130 will be increased by an appropriate amount.
  • the (-) negative voltage of the sensed position signal (V SP ) will approach the (+) plus voltage on line 160.
  • the output of coil driver 136 will be the same polarity as the larger of the two, and proportional to the input voltage to control amplifier 132.
  • V SP sensed position signal voltage
  • V SP sensed position signal voltage
  • 114, 116, 118, 124 and 126 are used to adjust the gain of the output of sensors 58 and 60 and to insure that the two (2) outputs are equal at the center position of the armature 28 and spool 22.
  • Difference amplifier 120 combines the two sensor signals into a voltage signal that increases as a (-) negative voltage as the spool moves away from center (in this case, with a (+) positive command signal).
  • the driver 136 current output will be (+) positive and the (+) positive current will drive the armature and spool 22 to the left until the (-) negative voltage of the sensed position signal (V SP ) matches correctly with the (+) positive command signal at junction 130 to hold the spool in the required position.
  • the control amplifier 132 will have a (-) negative input causing a (-) negative output current to coils 54 and 56 sufficient to drive the spool to the right to the position that exactly holds the spool 22 at the correct position.
  • the function of the control system is the same as described for a (+) plus command, but all voltage polarities are reversed.
  • Figure 2a shows a preferred implementation of the current feedback system wherein the sensed current signal (V sc ), instead of being combined with the commanded position signal (V CP ), is combined with the output of difference amplifier 120.
  • An unity gain amplifier or buffer 121 which includes resistors 117 and 119, sums these two signals an provides the resulting signal (which represents a current compensated, sensed position signal) to resistor 128.
  • the remainder of the circuit is identical to that depicted in Figure 2. Possible component values for the circuit of Figure 2a are shown in the table below:
  • Resistor 126 25 Kohms.
  • Resistor 138 5 Ohms.
  • control loop of the present invention could readily implement the control loop of the present invention using a current comparison circuit (as opposed to voltage comparison) or a pulse-width modulated circuit.
  • the spring assembly 40 will drive the spool overcoming all forces acting on it.
  • the centering spring will be loaded by a spring retainer. Rod 38 will transmit the spring force to the armature 28.
  • the command signal had been such as to cause the spool 22 to go to the position to pass maximum flow at minimum pressure drop (i.e. , the pressure drop across port 16 to port 18 plus drop from port 69 to port 72), the same sequence of events will happen as when the command signal was to cause the spool to move to the point that flow starts to port 18.
  • the sensed position voltage (V SP ) will go to the same higher (-) negative level to match the higher (+) plus voltage on line 160.
  • the combined feedback signal at node 130 will increase as the current increases (see Figure 6).
  • the feedback signal from Hall effect sensors 58 and 60 include flux generated by permanent magnet 48 which is position related, and coils 54, 56, which is force related.
  • Figure 5 shows a control system the same as Figure 2 except that the current compensation system (amplifier 144, and resistors 138, 140 , 142, and 146) has been removed.
  • the control system per Figure 2 provides current feedback such as to eliminate the change in feedback signal with changes in current through coils 54, 56, at least at one position (start of flow) as shown in Figure 6.
  • the control system per Figure 5 does not include a current feedback signal.
  • Figure 8 shows that the resulting change in spool 22 position from position A to position B will be much larger than in Figure 6.
  • the friction force on the armature and spool will be a small percent of the total force at all working positions. The other forces acting on the spool and armature are significant.
  • Figure 4 shows a second design arrangement for a force motor.
  • the two coils 54 and 56 in Figure 1 are replaced by a single coil 160.
  • the permanent magnet 48 in Figure 1 is replacement by permanent magnet 162.
  • the permanent magnet flux circuit is the same as described above and shown in Figure 9.
  • the remainder of the function of the force motor of Figure 4 is the same as described above for the motor of Figure 1.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Servomotors (AREA)

Abstract

Cette invention se rapporte à un système de positionnement de servocommande (10), qui comprend un moteur force (26) répondant à un signal d'instruction (VCP) correspondant à un débit de soupape souhaité en faisant passer dans les bobines magnétiques (54, 56) un courant d'excitation destiné à produire une force de flux qui déplace la soupape (12). On prévoit de préférence deux capteurs à effet Hall (58, 60) qui détectent la position réelle (VSP) et fournissent un signal de retour à une boucle de commande, laquelle compare la position détectée (VSP) avec la position instruite (VSP). On positionne la soupape (12) en ajustant le courant d'excitation appliqué aux bobines magnétiques (54, 56). Ce système comporte en option des circuits destinés à corriger l'erreur entre la position réelle et la position instruite, produite par les variations de courant dans les bobines magnétiques (54, 56).
PCT/US1998/011736 1998-06-05 1998-06-05 Systeme de positionnement de servocommande WO1999063232A1 (fr)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1259937A2 (fr) * 1999-04-23 2002-11-27 Clark Equipment Company Caracteristiques d'un ordinateur central de commande pour une machine motrice
CN101476635A (zh) * 2008-12-19 2009-07-08 上海诺玛液压系统有限公司 用于直动式电液伺服阀衔铁组件的装配工装方法及装置
CN103195767A (zh) * 2013-04-12 2013-07-10 长春航空液压控制有限公司 一种直动调节式力矩马达流量伺服阀
CN105570226A (zh) * 2016-03-15 2016-05-11 海门市油威力液压工业有限责任公司 数字式音圈电机控制伺服阀

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3561488A (en) 1969-07-01 1971-02-09 Sanders Associates Inc Fluid flow control valve
US3835888A (en) * 1971-12-07 1974-09-17 Bosch Gmbh Robert Electro hydraulic servo control valve
US4251762A (en) * 1979-03-16 1981-02-17 Moog Inc. Armature position detector
US4605197A (en) 1985-01-18 1986-08-12 Fema Corporation Proportional and latching pressure control device
US4665348A (en) * 1984-08-09 1987-05-12 Synektron Corporation Method for sensing and controlling the position of a variable reluctance actuator
US4992766A (en) * 1988-07-25 1991-02-12 Honda Giken Kogyo Kabushiki Kaisha Linear actuator
US5244022A (en) 1992-09-25 1993-09-14 Borg-Warner Automotive, Inc. Fuel flow activated fuel vapor control apparatus
US5249603A (en) 1992-05-19 1993-10-05 Caterpillar Inc. Proportional electro-hydraulic pressure control device
US5257014A (en) * 1991-10-31 1993-10-26 Caterpillar Inc. Actuator detection method and apparatus for an electromechanical actuator
US5264813A (en) 1992-05-19 1993-11-23 Caterpillar Inc. Force motor having temperature compensation characteristics
US5787915A (en) * 1997-01-21 1998-08-04 J. Otto Byers & Associates Servo positioning system

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3561488A (en) 1969-07-01 1971-02-09 Sanders Associates Inc Fluid flow control valve
US3835888A (en) * 1971-12-07 1974-09-17 Bosch Gmbh Robert Electro hydraulic servo control valve
US4251762A (en) * 1979-03-16 1981-02-17 Moog Inc. Armature position detector
US4665348A (en) * 1984-08-09 1987-05-12 Synektron Corporation Method for sensing and controlling the position of a variable reluctance actuator
US4605197A (en) 1985-01-18 1986-08-12 Fema Corporation Proportional and latching pressure control device
US4992766A (en) * 1988-07-25 1991-02-12 Honda Giken Kogyo Kabushiki Kaisha Linear actuator
US5257014A (en) * 1991-10-31 1993-10-26 Caterpillar Inc. Actuator detection method and apparatus for an electromechanical actuator
US5249603A (en) 1992-05-19 1993-10-05 Caterpillar Inc. Proportional electro-hydraulic pressure control device
US5264813A (en) 1992-05-19 1993-11-23 Caterpillar Inc. Force motor having temperature compensation characteristics
US5244022A (en) 1992-09-25 1993-09-14 Borg-Warner Automotive, Inc. Fuel flow activated fuel vapor control apparatus
US5787915A (en) * 1997-01-21 1998-08-04 J. Otto Byers & Associates Servo positioning system

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1259937A2 (fr) * 1999-04-23 2002-11-27 Clark Equipment Company Caracteristiques d'un ordinateur central de commande pour une machine motrice
EP1259937A4 (fr) * 1999-04-23 2006-05-24 Clark Equipment Co Caracteristiques d'un ordinateur central de commande pour une machine motrice
CN101476635A (zh) * 2008-12-19 2009-07-08 上海诺玛液压系统有限公司 用于直动式电液伺服阀衔铁组件的装配工装方法及装置
CN103195767A (zh) * 2013-04-12 2013-07-10 长春航空液压控制有限公司 一种直动调节式力矩马达流量伺服阀
CN105570226A (zh) * 2016-03-15 2016-05-11 海门市油威力液压工业有限责任公司 数字式音圈电机控制伺服阀

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