JP2005240974A - Fluid pressure actuator, its operation method, and steering system of aircraft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid pressure actuator and its operation method for achieving high speed, suppressing generation of heat, and realizing dynamic control of a slant face angle of a swash plate, and also to provide a steering system of an aircraft. <P>SOLUTION: This fluid pressure actuator is composed of a fluid pressure cylinder 2, a fluid pressure pump 3 for supplying and discharging working fluid to/from an output piston 17, and an electric motor 1. The pump 3 is formed by a piston 13 and a piston 14 for distributing working fluid. The pistons advance and retract at respective phases and are slidably joined with the swash plate 4. An angle of a slant face of the swash plate 4 and the number of revolutions of the electric motor 1 are correlatively controlled. The number of revolutions of the electric motor is controlled by the number of control revolutions corresponding to a plurality of detection signals. The detection signal includes output signals corresponding to speed V and output F of the output piston. The number of revolutions of the motor is controlled according to control rules. The control rules decide the slant face angle and the number of revolutions corresponding to a speed signal and an output signal. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fluid pressure actuator, an operation method thereof, and an aircraft steering system, and more particularly, to a fluid pressure actuator including a swash plate, an operation method thereof, and an aircraft steering system.

  A driving machine that drives a driving object such as a robot hand, a rudder of a ship, and a steering wing of an aircraft is called an actuator and is used in various ways. A large reaction force acts on a drive-related part of a mechanical element that applies an external force to a large mass object. In order to move the movement (displacement) target object from position A to position B and to stop and fix the movement target object at position B, a servo motor for controlling the position of the fluid pressure pump or the piston of the fluid pressure pump is used. Used. Such a mechanical element is required to have a holding force for receiving and holding a large reaction force during movement and stoppage.

  As such an actuator, EHA (electric fluid pressure actuator) is known. The fluid pressure cylinder device based on the EHA principle is formed by an electric motor, a fluid pressure pump, and the above-described mechanical element (output piston) which is a drive related part. The operation end faces of the plurality of pistons of the fluid pressure pump are slidably rotated with respect to the inclined surface of the relatively rotating swash plate. A mechanical element that applies a large force to move the object to be driven or stops at a specified drive position with high accuracy (eg, an output piston that drives a robot hand that holds a mass object while stopping at a stop position) ) Has a large reaction force. The large reaction force is transmitted to the rotor of the electric motor through the fluid pressure pump. In order to hold the rotor in the control position, a large electric power is passed through the electric motor, and an excessive current is generated in a plurality of parts of the motor. The actuator based on the EHA principle constitutes an important mechanical element for suppressing such an excessive current by using a swash plate.

  For high-speed and high-precision control of an actuator that receives a large external force as a reaction force, a new control of the dynamic slope angle of the swash plate is required. In that case, it is important to increase the speed and accuracy of the control corresponding to the change in the amount of fluid contained in the fluid system including the fluid pressure pump.

JP 2001-295802 A

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluid pressure actuator that realizes dynamic slope angle control of a swash plate, an operation method thereof, and an aircraft steering system.
Another object of the present invention is to provide a fluid pressure actuator that is reduced in size and weight by suppressing generation of excessive current, an operation method thereof, and an aircraft steering system.
Still another object of the present invention is to provide a fluid pressure actuator that suppresses generation of heat by suppressing generation of excessive current and realizes a reduction in size and weight of an electric motor, an operation method thereof, and an aircraft steering system. is there.
Still another object of the present invention is to provide a fluid pressure actuator, an operation method thereof, and an aircraft steering system that further realize high speed and high accuracy.

  The fluid pressure actuator according to the present invention includes a drive system, a fluid system that controls the amount of fluid by the output of the drive system, and a control system. The fluid system is formed by a fluid pressure cylinder (2) and a fluid pressure pump (3) driven by a drive system by supplying and discharging working fluid to and from an output piston (17) of the fluid pressure cylinder (2). . The fluid pressure pump (3) is moved forward and backward in the main body (5) and in a phase different from each other in the main body (5), and a plurality of supply / discharge pistons (13, 14) supplying and discharging fluid to and from the output piston (17) ) And an inclined surface forming body (4 ′: commonly referred to as a swash plate in the industry, which is joined to a plurality of supply / discharge pistons (13, 14) and advances / retreats the supply / discharge pistons (13, 14). , Referred to as a swash plate). The drive system constitutes an electric motor (1) that performs relative rotation between the swash plate (4 ') and the main body (5). The control system includes a position control system that feedback-controls the output piston (17) to a target position corresponding to the position of the output piston (17), an output (F) of the output piston (17), and a target of the output piston (17). An angle control system (32, 24) for controlling the slope angle (37: θ) of the swash plate (4 ′) corresponding to the speed (V), the target speed (V), the output (F), and the slope angle ( and a rotation speed control system for controlling the rotation speed (101) of the electric motor (1) corresponding to θ). The plurality of supply / discharge pistons (13) moving forward and backward with different phases can move the output piston continuously in the same direction. Such advancing and retracting movement is executed by the rotation of the swash plate (4 ').

  The multi-variable control of the target speed and the slope angle of the present invention is executed in a known feedback control system that controls the output piston (17) to the target position. The slope angle is controlled in correlation with the rotation speed (101). Such correlation control or mapping control is performed by correlating the slope angle of the swash plate (4 ′) with the rotational speed (101) faithfully corresponding to the real-time state quantity of the entire system (drive system and fluid system). By appropriately determining, the slope angle can be dynamically controlled. Such dynamic control realizes basic control technology for high-precision control and miniaturization and weight reduction, which will be described later.

  The control of the position control loop is based on the difference between the output piston (17) and the target position, the positive / negative of the rotation direction of the electric motor (1) is determined, and the total rotational speed is controlled by feedback control so that the difference becomes zero. The point to be controlled is the same as the control of the known technique. In the present invention, two variables of the rotational speed (N: roughly corresponding to the target speed) and the slope angle (37: θ) are controlled in real time. Although it is effective to use past empirical rules to execute such control by mapping rules, optimal control is calculated by calculation based on theoretical evaluation functions or empirical evaluation functions. It is preferable. Mapping rules are referenced for real-time control. It is remarkably effective for high accuracy that the simultaneous control of the rotational speed and the slope angle is executed at the same time series point as the feedback control for position control.

  In the rotation speed / slope angle control, the reaction force is appropriately reduced in real time on the time series point of the high-precision position control by the appropriate slope angle θ at which the motor is controlled by a large external force reaction, and the generation of excessive current is suppressed. As a result, the motor can be reduced in size and weight. A robot hand is preferably exemplified as such an actuator that is particularly required to be reduced in size, and an aircraft steering system is preferably exemplified as such an actuator that is particularly required to be reduced in weight.

  The rotation speed control system has a rotation speed control rule. The rotational speed control rule includes a calculation rule for calculating the target speed (V) corresponding to the position deviation (32) between the position (34) of the output piston (17) and the target position (33), and the target speed (V). And a rotation speed mapping rule (44) that defines the rotation speed of the electric motor corresponding to the output (F) and the slope angle (θ). The angle control system has an angle control rule. The angle control rule forms an angle mapping rule (45) that defines the slope angle (θ) corresponding to the output (F) and the target speed (V). The controlled object is two variables, and the variables describing the two variables are two variables or three variables, and the mapping rules divided into regions are well reflected in actual proper operation.

  It is remarkably effective for the control rule that the flow rate corresponding to the speed (V) and the outflow amount corresponding to the output correspond to the speed (V) for high accuracy. In many fluid machines, the fluid of the system is actively used as a lubricating fluid. It is important that the change in the fluid amount is reflected in the position control. The rotational speed is corrected in accordance with the fluid amount. In EHA, the main body is always divided into a rotating part (5) and a non-rotating part (6) for continuous fluid supply and discharge. In the rotating sliding surface (7) between the rotating part (5) and the non-rotating part (6), the fluid of a part (11, 21) of the fluid system is positively used for lubrication. The lubricating fluid is actively released from the sliding surface (7) to the outside of the fluid system (it is said to leak in the field). The fluid in the pressure fluid supply / discharge chamber (8) is positively released from the sliding surface between the supply / discharge piston (13) and the non-rotating body (5). Furthermore, the fluid in the fluid system is supplied to the sliding surfaces of the supply / discharge piston (13) and the inclined plate (4 ') for lubrication. In addition, there is a site where the in-system fluid is partially released from the system or leaks. In this way, the amount of fluid decreases and is not constant. Fluid replenishment is effective in order to make the amount of fluid constant. The outflow amount of the fluid and the replenishment amount of the fluid in the system are described in the calculator as parameters unique to each fluid machine. Controlling the rotation speed and the slope angle as described above corresponding to such a fluid change amount is a control system premised on high-speed control, and position control can be made highly accurate. Higher accuracy appears as an improvement in responsiveness in real-time time-series control.

  The control law obtains the first slope angle (θ1) corresponding to the target speed (V: Step S4 in FIG. 6), and obtains the second slope angle (θ2) corresponding to the output (F). A selection rule for selecting the smaller one of the angle (θ1) and the second slope angle (θ2) as the slope angle (θ) is included. A smaller angle is preferable because the slope angle is proportional to the reaction force. The control law further includes a restriction law that limits the rotational speed (rotational speed) of the electric motor to the maximum rotational speed or less in the operation process of moving the output piston (17) to the target position. Mechanical damage is prevented from occurring by operating the actuator at a high speed exceeding the limit. It is preferable that the control rule further includes a restriction rule that keeps the slope angle (θ) within the range of the maximum angle and the minimum angle in order to prevent the invalidity of the slope and the excessive use of the slope.

  The present invention is utilized for an aircraft steering system, and its usefulness is remarkably utilized. An aircraft equipped with the above-described fluid pressure actuator includes a steering rudder (64-1, 2) and a steering control computer (67). The output piston (17) is mechanically connected to the steering rudder (64-1, 2). The steering control computer (67) outputs a steering command. The steering command corresponds to the position signal of the pilot's manual pilot. The target position (33) of the output piston corresponds to the position signal.

  The fluid pressure pump (3) including the fluid pressure cylinder (2) and the swash plate (4 ') and the electric motor (1) are formed as an actuator unit (51) mechanically coupled. A plurality of actuator units (51) are used. The aircraft steering rudder is arranged on the main wing (57) of the aircraft, a plurality of first steering gears (64), and a plurality of second steering rudder (66) arranged on the horizontal or vertical tail (61). , And other equipment that is equivalent to a steering wheel. The actuator units (51) are arranged in a distributed manner corresponding to the plurality of first steering units and the plurality of second steering units. In this case, it is particularly preferable that the plurality of actuator units (51) are arranged substantially mirror-symmetrically with respect to the center plane of the airframe. Such a mirror-symmetric arrangement makes the steering performance in the turning direction symmetric and facilitates computer calculations or pilot maneuvers. Integrated control of a plurality of actuators is centrally executed by a separately provided flight control computer.

  The unitization of a plurality of actuators is structured as a mechanical system unit in which a fluid pressure pump (3) including a fluid pressure cylinder (2) and a swash plate (4 ') and an electric motor (1) are mechanically coupled to each other. The The electrical wiring and fluid piping of the fluid system and the drive system are configured to be short inside each actuator, and the wiring and piping do not become redundantly long by routing the wiring and piping throughout the entire machine body. For this reason, the cause of mechanical failure is reduced, and the individual actuator units are structured in a compact manner, resulting in a reduction in weight. Such weight reduction is significantly effective in robots and aircraft in which many units are used.

  The operating method of the actuator according to the present invention is an operating method of the actuator that operates the actuator based on the EHA principle that rotates the fluid pressure pump by the rotational force of the electric motor and moves the fluid pressure cylinder output piston back and forth. To the fluid supply / exhaust force of the fluid pressure pump, measuring the piston position of the output piston of the actuator, measuring the output of the output piston, and the difference between the piston position and the target position of the output piston. Feedback control of the position of the output piston at the time series control point, calculation of the target rotational speed of the electric motor corresponding to the difference, and the slope angle of the slope corresponding to the output and the target rotational speed of the output piston Calculate the control speed of the electric motor corresponding to the target speed corresponding to the target rotational speed, output and slope angle. It is composed of a calculating number. The electric motor is rotationally controlled in real time by a plurality of control variables such as a control rotational speed and a slope angle. The calculation of the control rotational speed takes into account the amount of change in the fluid in the fluid system including the fluid pressure pump, and realizes high-speed, high-accuracy and high-response control.

  The fluid pressure actuator, the operation method thereof, and the aircraft steering system according to the present invention realize dynamic slope angle control of a swash plate in time-series feedback control. The slope angle correlated with the rotational speed is controlled, the load on the electric motor is reduced, and as a result, high-speed response control is realized. In addition, the generation of excessive current is suppressed, the electric motor is reduced in size and weight, and the use in fields such as aircraft and robots is expanded.

  The implementation of the fluid pressure actuator according to the invention is described in detail in correspondence with the figures. As shown in FIG. 1, the electric motor 1 is provided together with a fluid pressure cylinder 2 and a fluid pressure pump 3. The swash plate 4 is fixed and joined to the fluid pressure pump 3 and mechanically coupled.

  The main body of the fluid pressure pump 3 is formed of a rotating body 5 and a non-rotating body 6. The rotary body 5 is supported by a bearing casing (not shown) so as to be rotatable and slidable. The rotating main body 5 is joined to the non-rotating main body 6 via a rotating sliding surface 7 so as to be rotatable. The rotating body 5 forms a plurality of first pressure fluid supply / discharge chambers 8 and a plurality of second pressure fluid supply / discharge chambers 9. The first pressure fluid supply / discharge chamber 8 and the second pressure fluid supply / discharge chamber 9 are formed in the rotary body 5 as a plurality of pressure fluid supply / discharge holes extending in the coaxial line direction. As shown in FIG. 1, the first pressure fluid supply / discharge chamber 8 is connected to a first pressure fluid supply / discharge port 11. The second pressure fluid supply / discharge chamber 9 is connected to the second pressure fluid supply / discharge port 12. As shown in FIG. 2, the total number of the first pressure fluid supply / discharge chambers 8 and the second pressure fluid supply / discharge chambers 9 is set to an odd number (example: 7). The first pressure fluid supply / discharge chamber 8 and the second pressure fluid supply / discharge chamber 9 are arranged on the same circumference at equal angular intervals. As shown in FIG. 3, the first pressure fluid supply / exhaust port 11 and the second pressure fluid supply / exhaust port 12 are formed by being cut out by the rotary body 5 within the same angular range. The fluid supply / discharge pump based on the EHA principle supplies fluid in one direction to one side chamber of the output piston 17 while the rotary body 5 rotates in the same direction, and supplies fluid in one direction from the other side chamber of the output piston 17. Suction.

  A plurality of pump-side first pistons 13 are inserted into the plurality of first pressure fluid supply / discharge chambers 8, respectively. A plurality of second pump-side pistons 14 are inserted into the plurality of second pressure fluid supply / discharge chambers 9, respectively. The total number of the pump-side first piston 13 and the pump-side second piston 14 is 7 in the above-described example. The seven pistons reciprocate in the first pressure fluid supply / discharge chamber 8 and the second pressure fluid supply / discharge chamber 9 in a forward and backward phase.

  The outer end surfaces of the pump-side first piston 13 and the pump-side second piston 14 are formed into spherical surfaces, and the spherical surfaces are simultaneously joined to the swash plate 4 and slide relative to each other. The rotary body 5 is fixedly coupled to and connected to the output shaft of the electric motor 1 via the coupling shaft 15. The pump-side first piston 13 and the pump-side second piston 14 that are held by the rotating body 5 that receives the rotational driving force from the electric motor 1 rotate around a single coaxial line and are inclined. In response to the reaction from the plate 4, each moves forward and backward as described above.

  As shown in FIG. 1, the fluid pressure cylinder 2 is formed of a cylinder body 16 and an output piston 17. The output of the output piston 17 is taken out via the piston rod 18. The output provides operating force to a machine operating site such as a robot hand. The first pressure fluid supply / discharge port 11 is connected to one cylinder chamber 19 of the cylinder body 16 via a first pressure fluid passage 21, and the second pressure fluid supply / discharge port 12 is connected to the other cylinder chamber 22 of the cylinder body 16. The second pressure fluid passage 23 is connected.

  The rotary body 5 coupled to the output shaft 15 of the electric motor 1 rotates, and the pump-side first piston 13 and the pump-side second piston 14 receive their rotational forces as reaction forces from the inclined surface of the swash plate 4, and in the rotational direction. It moves forward and backward with a phase difference equal to the order. The pump-side first piston 13 or the pump-side second piston 14 that moves forward pushes the hydraulic oil in the first pressure fluid supply / discharge chamber 8 from the first pressure fluid supply / discharge port 11, and passes through the first pressure fluid passage 21. The pressure fluid is supplied to the one-side cylinder chamber 19 of the cylinder body 16 through the pressure chamber. The pump-side first piston 13 or the pump-side second piston 14 that moves backward transfers the working fluid in the other-side cylinder chamber 22 from the second pressure fluid supply / discharge port 12 via the second pressure fluid passage 23. Suction into the supply / discharge chamber 9. In such a motion, the slope angle between the slope of the swash plate 4 and the rotation surface of the rotary body 5 (surface orthogonal to the rotation axis) is determined by the pump-side first piston 13, the pump-side second piston 14 and the swash plate. The magnitude of the reaction force between 4 and 4 is determined. If the slope angle is zero, the transmission force between the pump-side first piston 13, the pump-side second piston 14, and the swash plate 4 is zero.

  As shown in FIG. 4, a slope angle setting device 24 commonly used in a hydraulic pump is added. The swash plate 4 is reconfigured as a slope angle setting swash plate 4 '. The slope angle setting unit 24 is provided as a servo motor connecting screw for setting a slope angle or a servo fluid pressure cylinder for setting a slope angle. The operating end of the output shaft 25 is rotatably coupled to a part of the slope angle setting swash plate 4 '. The slope angle variable swash plate 4 ′ is supported by a fulcrum shaft 26 so as to be rotatable about a fulcrum shaft 26 orthogonal to the coupling shaft 15 at an appropriate position. The movement distance of the forward and backward movement of the output shaft 25 corresponds to the slope angle of the slope angle setting swash plate 4 '. The output position is electrically detected by a position detector 28 that detects the position of a fixed point 27 of the piston rod 18 that moves in unison with the output piston 17.

  FIG. 5 shows a fluid pressure control circuit according to the present invention. The fluid pressure control circuit includes a subtractor 31 and a control law setting unit 32 that determines a control law of EHA. The subtracter 31 receives an actuator operation target position signal 33 and an actuator operation position signal (actuator position, specifically, the position of the output piston 17) 34 detected by the position detector 28. The subtractor 31 outputs a difference signal (position deviation signal) 35 of a difference between the actuator operation target position signal 33 and the actuator operation position signal 34 to the control law setting unit 32. The control law setter 32 generates and outputs a multivariable signal corresponding to the position deviation signal 35. The multivariable signal is formed from a target motor rotation speed command value 36 and a slope angle command value 37. The target motor rotation speed command value 36 is input to the electric motor control driver 38. The slope angle command value 37 is input to the slope angle setting unit 24. The slope angle setting unit 24 sets the slope angle corresponding to the slope angle command value 37 to the slope angle variable swash plate 4 ′ via the output shaft 25.

  A load that the piston rod 18 receives as a reaction force from the operation control target is detected by a load detector 39. The load detector 39 can detect the load by detecting the pressure difference of the working fluid in the one side cylinder chamber 19 and the other side cylinder chamber 22. The load detection signal 41 detected by the load detector 39 is input to the control law setting unit 32 as a feedback signal together with the actuator operation position signal 34 as described above. The electric motor 1 outputs the rotation speed signal 42 and the angular position signal 43 as feedback signals. The rotational speed signal 42 and the angular position signal 43 are input to the electric motor control driver 38 together with the motor rotational speed command value 36.

  FIG. 6 shows an implementation of the control method of the fluid pressure actuator according to the present invention. This realization has a control law. The control law outputs the motor rotation speed command value 101 and the slope angle command value 37 as output signals corresponding to the input signals formed from the actuator operation target position signal 33, the actuator operation position signal 34, and the load detection signal 41. It is a rule to do. In the initial step S 0, the actuator operation target position signal 33, the actuator operation position signal 34, and the load detection signal 41 are input to the control law setter 32. In step S <b> 1, the actuator operation position signal 34 is subtracted from the actuator operation target position signal 33 by the subtractor 31, and the position deviation 35 resulting from the subtraction is input to the control law setting unit 32.

  In step S 2, the position deviation 35 is a control process for reaching the actuator operation target position signal 33 from the actuator operation position signal 34. Not calculated). Step S3 determines a restriction on the motor rotation speed. If the calculated motor speed is greater than the maximum allowable speed, the motor speed is set to the maximum allowable speed. If the calculated motor speed is less than the maximum allowable speed, the motor speed is set. The number is set to the calculated rotational speed. Thus, the electric motor 1 does not rotate beyond the limit rotational speed.

  In step S4, a target speed (linear speed of the actuator output piston 17) V corresponding to the motor speed is calculated and obtained. The actuator linear speed V is calculated as a speed at which the time to reach the target position and the thrust of the output are appropriate. The target speed V is input to the motor rotation speed map 44 in step S5. The motor rotation speed map 44 is built in the control law setting unit 32.

  The actuator force (the thrust of the piston rod 18) F that is the load detection signal 41 is input to the slope angle map 45 together with the target speed V in step S6. The slope angle map 45 is built in the control law setting unit 32. The actuator force F is input to the slope angle map 45 and input to the rotation speed map 44 in step S5. The slope angle map 45 selects the slope angle θ corresponding to the target speed V and the actuator force F in step S6. The slope angle θ is input to the rotation speed map 44 together with the target speed V and the actuator force F in step S5.

  In step S7, the motor speed command value 101 corresponding to the target speed V, the slope angle command value θ37, and the actuator force F is calculated from the motor speed map 44 or obtained from the correspondence table and output from the motor speed map 44. Then, the motor rotation speed command value 101 is input to the electric motor control driver 38. The slope angle command value 37 is calculated by the slope angle map 45 or obtained from the correspondence table, and is output from the control law setting unit 32 and input to the slope angle setting unit 24.

  FIG. 7 shows an implementation of the rotation speed map 44 in step S5. The specific flow is set in the control law setting unit 32. In step S8, the piston movement corresponding flow rate (fluid flow rate corresponding to the linear movement amount of the output piston 17) necessary for the piston movement corresponding to the target speed V is calculated. The piston movement-corresponding flow rate is calculated from the target speed V and the sectional area of the output piston 17. In step S9, the fluid change amount in the fluid system corresponding to the actuator force F and inside the fluid system including the fluid pressure pump 3 is calculated. The amount of change can be known in advance by measurement in the fluid pressure system corresponding to the thrust of the output piston 17 or can be known by calculation hydrodynamically. Furthermore, the replenishment amount of the fluid is considered. In step S10, the target flow rate in the fluid pressure cylinder corresponding to the flow rate corresponding to the piston movement and the fluid change amount in the fluid system is calculated. In step S11, the motor rotation speed command value 101 is calculated as a value corresponding to the slope angle θ and the target flow rate in the fluid pressure cylinder. The motor rotation speed command value 101 is corrected by the amount of fluid change in the fluid system. Such correction is executed at the time series points described above, and in particular, executed at all times in the control cycle. In the present invention in which the slope angle and the motor rotational speed are controlled in correlation, the motor rotational speed is corrected in response to the change in the fluid flow rate, and the output piston 17 is controlled with higher accuracy and higher speed. High responsiveness of the actuator that receives a large external force is realized.

  FIG. 8 shows an implementation of the slope angle map 45 in step S6. The specific flow is set in the control law setting unit 32. In step S12, the speed corresponding slope angle θ1 of the slope angle variable swash plate 4 'corresponding to the actuator linear speed V is calculated. A small slope angle corresponds to a slow speed of the output piston 17 for the same motor rotational speed. In step S13, the thrust corresponding slope angle θ2 of the slope angle variable swash plate 4 'corresponding to the actuator force F is calculated. In step S14, the speed-corresponding slope angle θ1 and the thrust-corresponding slope angle θ2 are compared, and the small slope angle among them is selected as the selected slope angle θ (= Smin (θ1, θ2)). A smaller slope angle corresponds to a smaller reaction force generated in the electric motor 1 with respect to the thrust of the output piston 17. The smaller of θ1 and θ2 is represented by Smin (θ1, θ2).

Step S15 shows the slope angle limitation by the limiter. When the selected slope angle θs is larger than the set maximum slope angle θmax, the selected slope angle Smin (θ1, θ2) is set to the maximum slope angle θmax. When the selected slope angle Smin (θ1, θ2) is smaller than the set minimum slope angle θmin, the selected slope angle Smin (θ1, θ2) is set to the minimum slope angle θmin. When the selected slope angle Smin (θ1, θ2) is smaller than the maximum slope angle θmax and larger than the minimum slope angle θmin, the selected slope angle Smin (θ1, θ2) is directly equal to Smin (θ1, θ2) selected in step S14. Maintained. In this way, the slope angle θ37 in the proper range is determined by the control law setter 32 by the limiter and is input to the slope angle setter 24.
θmin ≦ θ = Smin (θ1, θ2) ≦ θmax

  FIG. 9 shows a specific example of the slope angle map 45 that executes slope angle control law mapping. In the three-dimensional coordinate system of FIG. 9, the vertical axis represents the output axis (θ), and the two horizontal axes represent the input axes (F, V). The vertical axis indicates the output slope angle (command value) 37, the first horizontal axis indicates the piston speed V determined in step S4, and the second horizontal axis indicates the actuator force F (piston thrust). The curved surface or approximate plane S is represented by S (θ, V, F) = 0, and is represented by θ = θ (V, F). The approximate plane S is adopted by theoretical calculation to which an empirical rule obtained by theoretical calculation or experiment is added. With more experience, the approximate plane S is corrected and corrected.

  The general plane S further has information on the motor rotational speed (rpm). For convenience of illustration, the motor rotation speed command value is shown in stages in 10 regions R1 to R10. However, in the actual machine, it is not discretized as such and is continuous within the capacity of the computer. Yes. The figure illustrates one coordinate point (θ, V, F).

  FIG. 10 shows the amount of heat generated by the electric motor 1 for an actual machine that is operated with the slope angle θ determined by the above-described map and the motor rotation speed command value 101. The two-dimensional coordinate axis is formed from the target speed V of the piston and the actuator force F. The vertical axis represents the amount of heat generation. The approximate curved surface shows a calorific value distribution of a two-variable function. 11A, 11B, and 11C show two-dimensional cross sections of the calorific value-actuator force in FIG. 10 for three specific target speeds (target speeds A, B, and C in FIG. 10) selected in FIG. Show. In the EHA of the variable swash plate of the present invention compared to the known fixed swash plate, the amount of heat generation is reduced by a maximum of 70% in the entire region.

  FIG. 12 and FIG. 13 show graphs for confirming responsiveness by numerical analysis for an actual machine that is driven by the control law of the present invention having the above-described effect of reducing the amount of heat generation. In FIG. 12, the vertical axis represents the amplitude ratio and the horizontal axis represents the frequency. In FIG. 13, the vertical axis indicates the phase and the horizontal axis indicates the frequency. The horizontal axis is represented on a logarithmic scale. For a real machine, a stationary sine wave is input to the limiting element for response evaluation, and the amplitude ratio and phase of the output waveform are measured. As shown in FIG. 12, in the present invention, attenuation is improved over the entire frequency range. As shown in FIG. 13, in the present invention, the phase delay is improved in the practical frequency range.

  14 to 16 show the application of the described implementation of the actuator according to the invention. The application relates in particular to the field of aircraft steering. As shown in FIG. 14, the fluid pressure actuators shown in FIG. 1 or FIG. 5 are arranged three-dimensionally as a plurality of sets at a plurality of dispersed positions in the aircraft body. As the electric motor 1, in particular, a servo motor that is highly accurate in position control and excellent in immediate response is adopted. The electric motor 1, the fluid pressure pump 3, and the fluid pressure cylinder 2 are mechanically integrated with each other as an actuator unit 51. Such unitization realizes weight reduction as described above. A manifold (see FIG. 5) 52 including a valve structure that performs linked control of the pressure fluid pressure between the first pressure fluid passage 21 and the second pressure fluid passage 23 is further integrated with the actuator unit 51. An accumulator 53 is added to smoothly control the partial pressure (positive pressure and negative pressure) of the pressure fluid with respect to the one side cylinder chamber 19 and the other side cylinder chamber 22 of the fluid pressure cylinder 2. The accumulator 53 is further integrated with the actuator unit 51.

  FIG. 15 shows an improvement of the actuator unit 51. In this implementation, the controller box 55 of the ACC 54 is further integrated into the actuator unit 51 and incorporated into the actuator unit 51. The transmission line for transmitting the motor rotation speed command value 36 and the slope angle command value 37 is mechanically integrated with the electric motor 1 and the fluid pressure pump 3, and the steering system is further reduced in size.

  FIG. 16 shows a distributed normal state of a plurality of sets of actuator units 51 arranged at a plurality of distributed positions in the aircraft body. The aircraft body 56 is formed of a body trunk 57, both-side main wings 58, both-side tails 59, and vertical tails 61. A plurality of other movable wings are arranged for steering. A slat 62 is disposed at the front edge portion of the both-side main wing 58, and an aileron 63 and a flap 64 are disposed at the rear edge portion of the both-side main wing 58. The flap 64 is formed of an inner string flap 64-1 and an outer string flap 64-2. An elevator 65 is disposed at the rear edge portion of the two-sided tails 59. A ladder 66 is disposed at the rear edge portion of the vertical tail 61.

  One slat 62 is equipped with two (or a plurality) of EHAs (corresponding to or corresponding to the actuator unit 51). One aileron 63 is equipped with two (or plural) EHAs 51 correspondingly. One flap 64-1 is equipped with two (or plural) EHAs 51 correspondingly. One outer string flap 64-2 is equipped with two (or plural) EHAs 51 correspondingly. One elevator 65 is equipped with two (or plural) EHAs 51 correspondingly. One vertical tail 61 is equipped with three (or plural) EHAs 51 correspondingly.

  For flight control, a flight control computer (FCC) 67, the actuator control computer (ACC) 54 described above, a slat / flap control computer (SFCC) 68, and a ground spoiler actuator Control computers (GACC) 69 are arranged in a distributed manner. In addition, a flight spoiler (FS) 71 and a ground spoiler (GS) 72 are arranged.

  The FCC 67 outputs a steering angle and other attitude control parameters corresponding to a steering (steering including body attitude control) target that controls the entire steering system. The ACC 54 is a control signal (example: motor rotation speed command value 36 and slope angle command value 37) based on the control law described above corresponding to the command signal (example: actuator operation target position signal 33) commanded from the FCC 67. Is output.

  One actuator unit 51 is reduced in weight as much as possible in terms of mass, and a large number (41 only shown) of actuator units 51 are arranged in a distributed manner throughout the entire body. The unitized ACCs 51 shown in FIG. 15 are distributed in a one-to-one correspondence with one operating body. In this case, the ACC is composed of a general ACC and distributed ACC elements. The plurality of actuator units are arranged substantially in mirror symmetry with respect to the center plane of the airframe. The ACC arranged corresponding to the position of the ladder 66 is arranged almost in the vicinity of the center plane, and maintains its mirror symmetry well.

FIG. 1 is a cross-sectional view showing an object to which the present invention is applied. 2 is a cross-sectional view taken along line II-II in FIG. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a cross-sectional view showing a realization state of the fluid pressure actuator according to the present invention. FIG. 5 is a circuit diagram showing a realization state of the fluid pressure actuator according to the present invention. FIG. 6 is a flowchart showing the control law of the realization state of the fluid pressure actuator according to the present invention. FIG. 7 is a flowchart showing another control law of the realization of the fluid pressure actuator according to the present invention. FIG. 8 is a flowchart showing still another control law of the realization of the fluid pressure actuator according to the present invention. FIG. 9 is a table showing a map of realization of the fluid pressure actuator according to the present invention. FIG. 10 is a graph showing the heat generation amount. FIG. 11A is a graph showing the heat generation amount. FIG. 11B is a graph showing other calorific values. FIG. 11C is a graph showing yet another heat generation amount. FIG. 12 is a graph showing the amount of attenuation. FIG. 13 is a graph showing the phase delay. FIG. 14 is an oblique projection showing unitization of the fluid pressure actuator. FIG. 15 is an oblique projection showing another unitization of the fluid pressure actuator. FIG. 16 is a cross-sectional plan view showing a distributed arrangement of the actuators in the aircraft.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electric motor 2 ... Fluid pressure cylinder 3 ... Fluid pressure pump 4 '... Swash plate 5 ... Main body (rotating part)
6 ... Non-rotating portion 13 ... Pump-side first piston 14 ... Pump-side second piston 17 ... Output piston 24 ... Slope angle controller 44 ... Motor rotation speed mapping rule 45 ... Slope angle mapping rule V ... Speed F ... Output θ ... Slope angle θ1 ... 1st slope angle θ2 ... 2nd slope angle

Claims (13)

A drive train,
A fluid system that controls the amount of fluid by the output of the drive system;
With control system,
The fluid system is
A fluid pressure cylinder;
A fluid pressure pump that supplies and discharges working fluid to and from the output piston of the fluid pressure cylinder and is driven by the drive system;
The fluid pressure pump is
The body,
A plurality of supply / discharge pistons that move forward and backward in the main body and have different phases and supply / discharge fluid to and from the output piston;
A swash plate that is joined to the plurality of supply / discharge pistons and moves the supply / discharge pistons forward and backward,
The drive system includes an electric motor that performs relative rotation between the swash plate and the main body,
The control system is
A position control system that feedback-controls the output piston to a target position corresponding to the position of the output piston;
An angle control system for controlling a slope angle of the swash plate corresponding to an output of the output piston and a target speed of the output piston;
A fluid pressure actuator comprising: a rotation speed control system that controls the rotation speed of the electric motor in accordance with the target speed, the output, and the slope angle. The fluid pressure actuator according to claim 1, wherein the control system executes the rotation speed control of the rotation speed control system and the angle control of the angle control system at the same time series point. The rotational speed control system has a rotational speed control rule;
The rotation speed control rule is:
A calculation rule for calculating the speed corresponding to a positional deviation between the position of the output piston and a target position;
A rotation speed mapping rule that defines the rotation speed of the electric motor corresponding to the target speed, the output, and the slope angle;
The fluid pressure actuator according to claim 2, wherein the angle control system includes an angle control rule, and the angle control rule includes an angle mapping rule that defines the slope angle corresponding to the output and the target speed. 4. The fluid pressure according to claim 3, wherein the calculation rule includes a correction rule for correcting the rotational speed corresponding to an outflow amount of fluid flowing out of the fluid system corresponding to the flow rate corresponding to the target speed and the output. Actuator. The main body includes a rotating portion and a non-rotating portion, and the supply / discharge piston moves forward and backward in the rotating portion,
The outflow amount includes a fluid that flows out from a sliding surface between the supply / discharge piston and the rotating portion, and a fluid that flows out from a sliding surface between the rotating portion and the non-rotating portion. The fluid pressure actuator according to claim 4, wherein the fluid amount of both or one of the fluids is included. The angle control rule obtains a first slope angle corresponding to the target speed, obtains a second slope angle corresponding to the output, and sets the smaller one of the first slope angle and the second slope angle as the first slope angle. The fluid pressure actuator according to claim 3, further comprising a selection rule that selects the slope angle. The fluid pressure actuator according to claim 6, wherein the angle control rule includes a restriction rule that keeps the slope angle within a range between a maximum angle and a minimum angle. The fluid pressure actuator according to claim 3, wherein the rotation speed control rule includes a restriction rule that defines a maximum value of the rotation speed. An aircraft steering system equipped with the fluid pressure actuator according to claim 1,
A steering control computer,
The output piston is mechanically connected to the steering rudder;
The steering control computer outputs a steering command corresponding to the position of the output piston,
The number of revolutions is controlled in response to the steering command. The fluid pressure cylinder, the fluid pressure pump, and the electric motor are formed as an actuator unit that is mechanically coupled, and a plurality of the actuator units are arranged,
The rudder is provided as a set of a plurality of rudders arranged at a plurality of positions on the main wing,
The aircraft steering system according to claim 9, wherein the actuator units are arranged in a distributed manner corresponding to the plurality of rudders. The aircraft steering system according to claim 10, wherein the plurality of actuator units are arranged substantially mirror-symmetrically with respect to a center plane of the fuselage. An operation method of an actuator for operating an actuator based on the EHA principle of rotating a fluid pressure pump by a rotational force of an electric motor and moving a fluid pressure cylinder output piston back and forth,
Converting the rotational force of the electric motor into fluid supply / discharge force of a fluid pressure pump;
Measuring the piston position of the output piston of the actuator;
Measuring the output of the output piston;
Feedback control of the position of the output piston at a time-series control point corresponding to the difference between the piston position and the target position of the output piston;
Calculating a target rotational speed of the electric motor corresponding to the difference;
Calculating a slope angle of the slope corresponding to the output and a target rotational speed of the output piston;
And calculating a control rotational speed of the electric motor corresponding to the target speed in correspondence with the target rotational speed, the output, and the slope angle.   The method of operating an actuator according to claim 12, wherein the calculation of the control rotational speed takes into account the amount of fluid change in the fluid system including the fluid pressure pump.

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