CN104271950B - Horsepower restricting means and horsepower method for limiting - Google Patents
Horsepower restricting means and horsepower method for limiting Download PDFInfo
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- CN104271950B CN104271950B CN201380022689.1A CN201380022689A CN104271950B CN 104271950 B CN104271950 B CN 104271950B CN 201380022689 A CN201380022689 A CN 201380022689A CN 104271950 B CN104271950 B CN 104271950B
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- horsepower
- oil pressure
- pressure pump
- pump unit
- flow
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/06—Control using electricity
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/08—Regulating by delivery pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B2205/00—Fluid parameters
- F04B2205/05—Pressure after the pump outlet
Abstract
Horsepower restricting means (101) of the present invention possesses: the pressure detector (5) detecting the head pressure of oil pressure pump unit; Horsepower based on discharge flow rate instruction oil pressure pump unit being sent to horsepower restriction limits rear flow instruction and exports the parallel feedforward compensator (9) of the offset for compensating the head pressure detected by pressure detector; Head pressure after compensating based on the offset exported by parallel feedforward compensator and the horsepower limits value of oil pressure pump unit that presets and calculate the flow restriction value calculating part (11) of the limits value of the discharge flow rate of oil pressure pump unit; Flow instruction with the discharge flow rate based on the flow restriction value calculated by flow restriction value calculating part and control oil pressure pump unit, exports flow instruction after horsepower restriction the constrictor (12) of oil pressure pump unit to.
Description
Technical field
The present invention relates to horsepower method for limiting and the horsepower restricting means of the discharge flow rate of the head pressure restriction oil pressure pump unit based on oil pressure pump unit.
Background technique
Generally speaking, for performing in the system of oil pressure actuated, oil pressure pump using motor and motor etc. as power source, and discharges working oil by rotary actuation, discharges oil and is supplied to oil pressure final controlling element via control valve.The horsepower W [kW] of pump is according to discharge flow rate Q [L/min] and head pressure P [MPa], efficiency eta, is tried to achieve by following formula;
…（9）；
But, according to the difference of the working environment of oil pressure final controlling element, and exist as because of excessive load oil pressure final controlling element temporarily stop situation.Under these circumstances, the head pressure of oil pressure pump increases, and the output of pump increases.Consequently, the load that the power source of pump carries also increases, thus in motor, causes dropout (trip), if motor then causes engine stop.
In the past, in oil pressure pump, when the head pressure of pump improves, in order to avoid motor and motor etc. become excess load, and perform the horsepower restriction of the discharge flow rate reducing pump.In the horsepower restriction of the discharge flow rate of the head pressure restrictive pump based on such pump, relative to the horsepower limits value Wm [kW] preset, the flow restriction value Qm [L/min] of the flow of restrictive pump is calculated by following formula;
…（10）；
And, make the flow instruction value of the discharge flow rate of control pump be less than flow restriction value Qm [L/min] and the discharge flow rate of restrictive pump performs horsepower restriction (such as with reference to patent documentation 1) with this.
Prior art document:
Patent documentation:
Patent documentation 1: Japanese Unexamined Patent Publication 7-208403 publication.
Summary of the invention
The problem that invention will solve:
But, in the horsepower restriction of existing oil pressure pump, after the change of flow instruction value, to the head pressure change of pump, there is operating lag, therefore cause flow restriction value be in the meantime changed to required more than, there is the problem occurring every now and then to vibrate.
The present invention is formed to solve such problem, its objective is in the oil pressure pump unit under horsepower restriction the vibration reduced because the operating lag of the head pressure of the oil pressure pump unit relative to flow instruction value causes.
The means of dealing with problems:
In order to solve the problem, the horsepower restricting means according to a form of the present invention possesses: the pressure detector detecting the head pressure of oil pressure pump unit; Horsepower based on the discharge flow rate instruction described oil pressure pump unit being sent to horsepower restriction limits rear flow instruction and exports the parallel feedforward compensator of the offset for compensating the head pressure detected by described pressure detector; Head pressure after compensating based on the offset exported by described parallel feedforward compensator and the horsepower limits value of described oil pressure pump unit that presets and calculate the flow restriction value calculating part of the limits value of the discharge flow rate of described oil pressure pump unit; With based on the flow restriction value calculated by described flow restriction value calculating part and the flow instruction of discharge flow rate controlling described oil pressure pump unit, export flow instruction after described horsepower restriction the constrictor of described oil pressure pump unit to.
According to said structure, the head pressure of the oil pressure pump unit detected by pressure detector is compensated by the offset exported by parallel feedforward compensator, and the limits value of the discharge flow rate of oil pressure pump unit is calculated based on the head pressure after this compensation and the horsepower limits value of the oil pressure pump unit preset, based on the flow instruction of this flow restriction value calculated with the discharge flow rate of control oil pressure pump unit, flow instruction after the restriction of oil pressure pump unit shaft horsepower, therefore in the oil pressure pump unit under horsepower restriction, the operating lag of the head pressure of the oil pressure pump unit relative to flow instruction can be compensated.Consequently, the vibration because operating lag causes can be reduced.
Also can be that described parallel feedforward compensator is made up of constant gain and band-pass filter.According to said structure, the operating lag of the head pressure of the oil pressure pump unit relative to flow instruction can be compensated preferably;
In order to solve the problem, the horsepower method for limiting of another form (aspect) of the present invention possesses: the head pressure detecting oil pressure pump unit; The offset that horsepower based on the discharge flow rate instruction described oil pressure pump unit being sent to horsepower restriction limits rear flow instruction and exports for compensating described detected head pressure; Head pressure after compensating based on the offset by described output and the horsepower limits value of described oil pressure pump unit that presets and calculate the limits value of the discharge flow rate of described oil pressure pump unit; With the flow instruction based on the described flow restriction value calculated and the discharge flow rate controlling described oil pressure pump unit, export flow instruction after described horsepower restriction to described oil pressure pump unit.
The output of described offset also can be that the parallel feedforward compensator be made up of constant gain and band-pass filter exports.
Invention effect:
The present invention possesses structure described above, and plays the effect of the vibration caused relative to the operating lag of the head pressure of the oil pressure pump unit of flow instruction value in the oil pressure pump unit that can reduce under horsepower restriction.
Above-mentioned purpose of the present invention, other objects, feature and advantage are with reference on the basis of accompanying drawing, are able to clearly by the detailed description of following preferred example.
Accompanying drawing explanation
Fig. 1 illustrates the block diagram used according to the schematic configuration example of the oil pressure actuated system of the horsepower restricting means of this example 1;
Fig. 2 is the block diagram of the formation example of the horsepower restricting means that Fig. 1 is shown;
Fig. 3 is the chart of the response wave shape that the head pressure after compensating in horsepower restriction controller is shown;
Fig. 4 is the chart illustrated by limiting the oil pressure pump characteristics obtained according to the horsepower of the first comparative example;
Fig. 5 is the chart illustrated by limiting the oil pressure pump characteristics obtained according to the horsepower of example 1;
Fig. 6 is the chart illustrated by limiting the analog result obtained according to the horsepower of the first comparative example;
Fig. 7 is the chart illustrated by limiting the analog result obtained according to the horsepower of example 1;
Fig. 8 is the block diagram of the formation example illustrated by the series filter limited according to the horsepower of the second comparative example;
Fig. 9 is the block diagram of the formation example illustrated by the series filter limited according to the horsepower of example 1;
Figure 10 is the baud line chart (Bodediagram) of the frequency characteristic illustrated by the series filter limited according to the horsepower of the second comparative example;
Figure 11 is the baud line chart (Bodediagram) of the frequency characteristic illustrated by the series filter limited according to the horsepower of example 1;
Figure 12 is the block diagram limited according to the horsepower of the oil pressure pump of the 3rd comparative example;
Figure 13 is the block diagram of the horsepower restricting means according to example 2 of the present invention.
Embodiment
With reference to accompanying drawing, example of the present invention is described.Below, in all of the figs identical symbol is marked with for same or equivalent key element, and omits repeat specification.
(example 1)
Fig. 1 illustrates the block diagram used according to the schematic configuration of the oil pressure actuated system of the horsepower restricting means of example 1 of the present invention.Oil pressure actuated system 100 possesses oil pressure pump 1, the motor 2 as the power source of oil pressure pump 1, oil pressure final controlling element 3, control valve 4, pressure transducer 5, operator 6, horsepower restriction controller 7, regulator 8.Here, pressure transducer 5 and horsepower restriction controller 7 form horsepower restricting means 101.Again, oil pressure pump 1, motor 2 and regulator 8 form oil pressure pump unit 102.In addition, below, input in regulator 8 exemplified with the command signal by making to include the flow instruction value limited by horsepower, control the structure of the discharge flow rate of oil pressure pump 1 with this, but such as also can be formed through and make this command signal input to the structure (with reference to another example) controlling the discharge flow rate of oil pressure pump 1 in motor 2 with this.
Oil pressure pump 1 such as using motor 2 as power source, and discharges working oil by rotary motion.Discharge oil to be supplied in oil pressure final controlling element 3 via control valve 4.As oil pressure pump 1, known oil pressure pump can be used.In this example, oil pressure pump 1 is such as driven with constant rotational speed by motor 2, and can be changed the variable displacement pump of the discharge flow rate (hereinafter referred to as flow) of oil pressure pump 1 by the adjustment at swash plate inclination angle.Power source is not limited to motor 2, such as, also can be explosive motor.
Oil pressure final controlling element 3 drives not shown load by the discharge oil of discharging from oil pressure pump 1.As oil pressure final controlling element 3, the oil hydraulic cylinder be such as exemplified.
Control valve 4 controls supply to the discharge oil of oil pressure final controlling element 3 and discharge, controls the action of oil pressure final controlling element 3 by means of this.Control valve 4 inputs according to the operation of user control signal that (the operation input indicated the action of final controlling element 3) export according to not shown controller and works.In addition, discharge work oil condition at control valve 4 from final controlling element 3, the working oil of this discharge is back to oil pressure pump 1 from control valve 4 by not shown oil circuit as pressure release oil.
Pressure transducer 5 detects the head pressure (hereinafter referred to as pressure) of oil pressure pump 1.Here, pressure transducer 5 is arranged at the supply from oil pressure pump 1 to oil pressure final controlling element 3 and discharges the oil circuit 20 of oil, and detects the pressure of the discharge oil supplied by oil circuit 20, the head pressure of this detection is exported in horsepower restriction controller 7.
In order to control oil pressure pump 1 discharge flow rate and by user operation operator 6.Here, operator 6 generates the command signal of the discharge flow rate of the oil pressure pump 1 corresponding with the operation amount of this operator 6, and exports horsepower restriction controller 7 to.
Horsepower restriction controller 7 is based on the head pressure of the oil pressure pump 1 detected by pressure transducer 5 and the command signal of the discharge flow rate of oil pressure pump 1 that inputted by operator 6, generate the command signal including the flow instruction value limited by horsepower, and exported to regulator 8.Here, flow instruction value is the tilt angle command value of the swash plate for controlling oil pressure pump 1.
Regulator 8 regulates the inclination angle of the swash plate of oil pressure pump 1 according to the tilt angle command value be comprised in the command signal of discharge flow rate, change the discharge flow rate of the oil pressure pump 1 in driving.
Then, Fig. 2 is used to illustrate the structure of horsepower restriction controller 7.Fig. 2 is the block diagram of the formation example that horsepower restricting means 101 is shown.As shown in Figure 2, horsepower restricting means 101 is made up of pressure transducer 5 and horsepower restriction controller 7.
Horsepower restriction controller 7 possesses series connection feed-forward compensator (parallelfeedforwardcompensator, hereinafter referred to as PFC) 9, adder 10, flow restriction value calculating part 11 and constrictor 12.Horsepower restriction controller 7 is such as by microcontroller, PLC(programmablelogiccontroller; Programmable logic controller (PLC)) etc. arithmetic mean unit form.PFC9, adder 10, flow restriction value calculating part 11 and constrictor 12 perform its built-in working procedure by arithmetic mean unit to realize with this.
PFC9 based on regulator 8 is sent horsepower restriction discharge flow rate instruction horsepower restriction after flow instruction value Qc [L/min] and the offset Pf [MPa] of actual value (head pressure of output) that exports for compensating the head pressure detected by pressure transducer 5.
Adder 10 is by the offset Pf [MPa] exported by PFC9 and detected by pressure transducer 5 and the actual value P [MPa] of the head pressure exported carries out add operation, and exports the head pressure value P ' [MPa] after compensating.
Flow restriction value calculating part 11 calculates the limits value Qm [L/min] of the discharge flow rate of oil pressure pump 1 based on the head pressure value P ' [MPa] after the compensation exported by the adder 10 and horsepower limits value Wm [kW] of oil pressure pump 1 that presets.Flow restriction value Qm [L/min] calculates based on following formula (1).
…（1）；
Here η is the efficiency of pump, and horsepower limits value Wm [kW] is such as pre-stored within the not shown memory section of horsepower restriction controller 7 inside.
Constrictor 12 is based on the flow restriction value Qm [L/min] calculated by flow restriction value the calculating part 11 and flow instruction value Qd [L/min] indicated the discharge flow rate of oil pressure pump 1, and the flow instruction value Qc [L/min] after being limited by horsepower exports oil pressure pump 1 to.Specifically, constrictor 12 compares flow instruction value Qd and flow restriction value Qm, when flow instruction value Qd is less than flow restriction value Qm, the flow instruction value Qc exported in oil pressure pump 1 is made to be flow instruction value Qd, when flow instruction value Qd is greater than flow restriction value Qm, the flow instruction value Qc exported in oil pressure pump is made to be flow restriction value Qm.Here flow instruction value Qd [L/min] is indicated by the operator 6 of Fig. 1, and is temporarily stored in the not shown memory section of horsepower restriction controller 7 inside.In addition, the memory section storing horsepower limits value Wm and flow instruction value Qd is the external storage of the storage or hard disk drive etc. of the inside of arithmetic mean unit, also can be the addressable storage device of computer connected by network in addition.
Then, the structure of PFC9 is described.PFC9 using horsepower limit after flow instruction value Qc as input value, export the offset Pf of the head pressure for compensating oil pressure pump, in this example, such as, be made up of constant gain and the band-pass filter with bivalent high-pass filter and low-pass first order filter.The transfer function Gf(s of PFC9) represented by following formula (2).
[mathematical expression 1]
。
[mathematical expression 2]
。
Here,
,
the cutoff frequency of bivalent high-pass filter,
be the cutoff frequency of low-pass first order filter, Kf is constant gain.
Fig. 3 is the chart of the response wave shape that the head pressure after being compensated by PFC9 is shown.The longitudinal axis represents pressure, horizontal axis representing time.Solid line represents the pressure P after PFC compensation ', dotted line represents pressure actual value P, and single dotted broken line represents PFC offset Pf.Shown here in certain load condition down-off command value with the response wave shape of pressure during stepped change.
Pressure actual value P is relative to the change of flow instruction value, and the starting of response is delayed by (during in figure td).In contrast, PFC offset Pf before pressure actual value P changes during produce the output of simulation in td.By means of this, the pressure P after PFC compensates ' seem and operating lag does not occur.
Like this, during the time lag (timelag) after the change of flow instruction value to the change of pressure actual value, the output of simulation can be produced by PFC9, therefore can the operating lag of compensatory pressure actual value.
Then, the concrete horsepower restriction process in horsepower restriction controller 7 is described.First, transfer function Gf(s continuous time of the PFC9 represented by formula (2)) be transformed to the such discrete time transfer function Gf(z of following formula (3) by the method for bilinearity change etc.).
[mathematical expression 3]
。
Now, the output Pf(k of the PFC9 of moment k) be calculate as follows.
[mathematical expression 4]
。
Then, by flow restriction value calculating part 11, use the pressure actual value P(k of moment k), the output Pf(k of PFC9) calculate the flow restriction value Qm(k of moment k as follows).Here, η is the efficiency considering pump, and make its along with pressure and flow etc. variable, more correctly can carry out horsepower restriction with this.
[mathematical expression 5]
。
Here, when being assumed to the flow restriction value Qm(k of moment k) be less than flow instruction value Qd(k), and when flow is limited, become Qc(k)=Qm(k).Therefore, the flow restriction value Qm(k of moment k) calculated by following formula (6).
[mathematical expression 6]
。
Then, by constrictor 12, at flow restriction value Qm(k) be actually less than flow instruction value Qd(k) time, make Qc(k)=Qm(k), traffic limits.
Like this, by the calculation of pressure flow restriction value after using compensation, do not exist with this and make flow instruction value be changed to required above situation, the vibration during horsepower therefore can be suppressed to limit.
(the first comparative example)
Then, the effect limited according to the horsepower of this example employing PFC9 and comparative example are carried out comparative illustration.First, the horsepower adopted in the prior art restriction is described as the first comparative example.
According in the horsepower restriction of the first comparative example, calculate actual value (horsepower of the output) W of horsepower according to the flow of oil pressure pump and the head pressure of oil pressure pump based on (9) formula.Again, relative to the horsepower limits value Wm [kW] preset, calculated the flow restriction value Qm [L/min] of the flow of restriction oil pressure pump by following formula;
…（7）；
And, when horsepower actual value W exceedes horsepower limits value Wm, the flow instruction value of the discharge flow rate controlling oil pressure pump is restricted to flow restriction value Qm [L/min], thus the discharge flow rate of restriction oil pressure pump, by means of the horsepower of this restriction oil pressure pump.
Fig. 4 is the chart illustrated by limiting the oil pressure pump characteristics obtained according to the horsepower of the first comparative example.The longitudinal axis represents the discharge flow rate of oil pressure pump, and transverse axis represents the head pressure of oil pressure pump.Curve Wm in this chart represents the horsepower restrictive curve of the point of flow and the pressure being connected to and reaching horsepower Wm.(the some a in figure ~ some i) is drawn and formed in the position of the flow in a certain moment and pressure by track P chronologically at regular intervals that represented by solid line.According in the restriction of the horsepower of the first comparative example, pressure increases and on the moment that an a represents, horsepower is more than Wm, flow instruction value is restricted to the flow being issued to horsepower Wm at the pressure of an a as indicated by the dotted lines.Similarly, at subsequent time b, if pressure increases, then flow instruction value is restricted to the flow being issued to horsepower Wm at the pressure of a b.Here, if do not changed while operating lag does not occur relative to the change pressure of flow instruction value, should be able to be converged on immediately on horsepower restrictive curve Wm by the track P of this operation.But, in fact there is operating lag, therefore when sending the instruction of the flow reaching horsepower Wm based on current pressure, as shown in Figure 4, an a b ~ c excessively reduces flow and on a d horsepower lower than Wm, or on an a d ~ e, excessively promote flow on the contrary and on a f horsepower more than Wm, repeatedly change with the form of crossing over horsepower restrictive curve like this.That is, vibrate.
In contrast, Fig. 5 illustrates that the horsepower by this example 1 limits the chart of the oil pressure pump characteristics obtained.Here the longitudinal axis represents the discharge flow rate of oil pressure pump similarly, and transverse axis represents the head pressure of oil pressure pump.Curve Wm in this chart represents the horsepower restrictive curve of the point of flow and the pressure being connected to and reaching horsepower Wm.(the some a in figure ~ some d) is drawn and formed in the position of the flow in a certain moment and pressure by track P chronologically at regular intervals that be illustrated by the broken lines.The position drafting at regular intervals chronologically of the flow in a certain moment and the pressure after being compensated by PFC is formed (some a ' ~ d ' in figure) by the track P ' represented by solid line.According in the restriction of the horsepower of this example 1, pressure increases and on the moment shown in an a, horsepower is more than Wm, flow instruction value is restricted to as indicated by the dotted lines at an a(=point a ') pressure be issued to the flow of horsepower Wm.Then, at next moment b, if pressure increases similarly, then flow instruction value is restricted to the flow that the pressure after the compensation of a b ' is issued to horsepower Wm as indicated by the dotted lines.Here, for the pressure after compensation by the operating lag of PFC compensation relative to flow instruction value, its delay is very little, and the track P ' therefore realized by this operation is converged on horsepower restrictive curve Wm at once.In addition, when the pressure after compensating is restrained, actual pressure trajectories P also converges on horsepower restrictive curve Wm.That is, vibration is reduced.
Then, each analog result of example 1 and the first comparative example is compared.Simulated conditions are that hypothesis flow instruction value Qd is 800 [L/min], horsepower limits value Wm is 200 [kW], the volume of oil hydraulic cylinder is 10 [L], and makes pressure release flow in 30 seconds, be changed to the situation of 250 [L/min] from 800 [L/min].
Fig. 6 is the chart illustrated by limiting the analog result obtained according to the horsepower of the first comparative example.Fig. 6 (a) illustrates waveform time response of horsepower actual value, and Fig. 6 (b) illustrates and limits by horsepower the oil pressure pump characteristics obtained.By analog result, in the first comparative example from occurred significantly to vibrate after 15 seconds near 20 seconds.
In contrast, Fig. 7 is the chart illustrated by limiting the analog result obtained according to the horsepower of example 1.Fig. 7 (a) illustrates waveform time response of horsepower actual value, and Fig. 7 (b) illustrates and limits by horsepower the oil pressure pump characteristics obtained.According to analog result, in this example, vibrate compared with the first comparative example and reduce;
(the second comparative example)
Then, the effect that horsepower basis being employed this example of PFC9 limits and the second comparative example contrast and are described.Second comparative example is formed as the structure possessing compensation circuit in the first comparative example.
Fig. 8 is the block diagram of the compensation circuit in the second comparative example.In fig. 8, G is control object (oil pressure pump etc.), and u is operation amount (flow instruction value), and y exports (pressure (actual pressure) after compensation), and F is the series filter (phase place shifts to an earlier date wave filter) as elements of compensation.Second comparative example in series possesses wave filter to compensate operating lag relative to control object (oil pressure pump).
In contrast, Fig. 9 is the block diagram of the compensation circuit in example 1.G is control object (oil pressure pump etc.), and u is operation amount (flow instruction value), and y exports (pressure after compensation), and H is parallel filter (PFC).As shown in Fig. 9 (a), in this example, possesses parallel filter in order to compensate operating lag relative to oil pressure pump.Here, when carrying out equivalence transformation to the block diagram of Fig. 9 (a), show as the series filter of Fig. 9 (b).Therefore, the series filter of the second comparative example is made to be F=1+
time, then obtain the effect identical with the parallel filter of this example (PFC).But,
generally comprise the differential term of high-order, therefore cannot utilize such wave filter in reality.Therefore, use the second comparative example of series filter as elements of compensation and structurally have essential distinction as this example of elements of compensation application parallel filter.
In addition, the effect of the series filter of the second comparative example and the parallel filter of this example is described.Figure 10 is the baud line chart of the frequency characteristic of the series filter illustrated according to the second comparative example.Figure 10 (a) illustrates gain diagram, and Figure 10 (b) illustrates phase diagram.Solid line represents the characteristic after compensation, H(s) represent the characteristic of series filter, G(s) represent the characteristic of control object.Control object G(s shown in high frequency region) delay increase, phase delay cannot be improved substantially.
In contrast, Figure 11 is the baud line chart of the frequency characteristic of the parallel filter illustrated according to example.Figure 11 (a) illustrates gain diagram, and Figure 11 (b) illustrates phase diagram.Solid line represents the characteristic after compensation, H(s) represent the characteristic of series filter, G(s) represent the characteristic of control object.In fig. 11, in low-frequency region, the characteristic after compensation and the characteristic G(s of control object) roughly equal, on the other hand, in high frequency region, the characteristic after compensation and the characteristic H(s of parallel filter) roughly equal, thus can phase delay be eliminated.
But in horsepower restriction, as the formula (7), horsepower limits value Wm obtains flow restriction value Qm divided by pressure P, but by this formula (7) at operating point (pressure
) surrounding when carrying out linearization, following formula (8) can be shown as.
[mathematical expression 7]
。
When regarding formula (8) feedback control of pressure as, known (60 η) Wm/
be equivalent to feedback gain, at the pressure of operating point
lower situation is issued to very large gain.In the theory of feedback control, if there is the frequency field of the operating lag of phase delay more than 180 degree, can become unstable when performing feedback with the gain of certain above size.
By the compensation that the series filter of the second comparative example carries out, cannot avoid reaching more than 180 degree in high frequency region phase delay, therefore may vibrate.On the other hand, the compensation undertaken by the PFC of this example, all can reduce phase delay in full rate region, it is hereby ensured and vibration is less likely to occur.
(the 3rd comparative example)
Then, the effect that horsepower basis being employed this example of PFC9 limits and the 3rd comparative example contrast and are described.3rd comparative example illustrates structure PFC being applied to the horsepower restriction in the feedback control of horsepower.
Under normal circumstances, PFC is applied to the phase reversal of controlled quentity controlled variable (output) and feeds back in (reverse feedback) such control controlled quentity controlled variable.The structure that horsepower when merely applying this PFC limits is shown in the block diagram of Figure 12.
But generally speaking, the horsepower of oil pressure pump is the product of discharge flow rate and head pressure, therefore the control object (flow → horsepower) of the block diagram of Figure 12 illustrates nonlinear characteristic, therefore directly can not apply the idea being compensated operating lag by PFC.
Therefore, in this example, utilize and can operate flow thus change pressure in oil pressure pump, and the pressure this point of this change can be measured, be formed as the structure as the block diagram of Fig. 2 with this.
By means of this, control object (flow → horsepower) illustrates substantially close to linear such characteristic, can apply the idea of the compensation of PFC.In addition, do not need the elements of compensation of PID controller etc. yet, horsepower restriction can be realized by very simple structure.
In addition, as shown in the block diagram of fig. 2, the pressure actual value of feedback is different with the dimension of command value (horsepower) for the structure limited according to the horsepower of this example, and the phase place of the pressure actual value of feedback is inverted.And, manage to utilize PFC with this by such pressure actual value is carried out feeding back with division form.On such point, the control of the horsepower restriction of this example is different in essence from common feedback control, and is the original structure that the oil pressure pump that can be represented by " horsepower=flow × pressure " could be derived.
(example 2)
Then use Figure 13 that example 2 of the present invention is described.In addition, omit the explanation of the structure common with example 1, different structures is only described.
Figure 13 is the block diagram of the horsepower restricting means according to example 2 of the present invention.This example compares difference with example 1, and horsepower restriction controller 7 also possesses plus and minus calculation device 13, using the input of the value that obtains after deducting flow instruction value Qd by plus and minus calculation device 13 from the flow instruction value Qc after horsepower restriction as PFC9.
Here, PFC9 revises the response in high frequency region substantially, therefore in the change of flow instruction value Qd not in the situation in such high frequency region (typically flow instruction value Qd situation about remaining unchanged), even if from the composition deducting flow instruction value Qd to the input of PFC9, do not affect the effect of PFC9 yet.By being formed as such structure, with this can to prevent when such as oil pressure pump 1 starts etc. uncharge state down-off command value from 0 stepped be promoted to specified value time, actual pressure does not rise, but the offset of PFC9 becomes large, and causes horsepower to limit situation about playing a role.
(other examples)
In above-mentioned each example, PFC9 is made up of constant gain and the band-pass filter with bivalent high-pass filter and low-pass first order filter, but is not limited thereto.As long as can compensate the structure of the operating lag of the head pressure of the oil pressure pump relative to flow instruction, then PFC9 such as can be made up of constant gain and another band-pass filter, also can only be made up of constant gain.
Again, in above-mentioned each example, in oil pressure pump 1, make the rotating speed of motor 2 remain unchanged, and after the instruction of tilt angle by flow instruction value transform being pump, perform the instruction sent to oil pressure pump 1, but be not limited thereto, also the tilt angle of oil pressure pump can be made to remain unchanged, and perform the instruction sent to oil pressure pump after the instruction of rotating speed by flow instruction value transform being motor.
By above-mentioned explanation, those skilled in the art understand more improvement of the present invention and other examples etc.Therefore, above-mentioned explanation only illustrates explanation, is to implement to provide for the purpose of most preferred form of the present invention to instruct to those skilled in the art.Without departing from the spirit of the invention within the scope, the particular content of its structure and/or function can be changed in fact.
Industrial applicability:
The present invention can be applied to the field of the oil pressure pump of the discharge flow rate of the head pressure restrictive pump based on oil pressure pump.
Symbol description:
1 oil pressure pump;
2 motors;
3 oil pressure final controlling element;
4 control valves;
5 pressure transducers;
6 operators;
7,70 horsepowers of restriction controllers;
8 regulators;
9PFC(parallel feedforward compensator);
10 adders;
11 flow restriction value calculating parts;
12 constrictor;
13 plus and minus calculation devices;
20 oil circuits;
100 oil pressure actuated systems;
101 horsepowers of restricting meanss;
102 oil pressure pump unit.
Claims (6)
1. a horsepower restricting means, possesses:
Detect the pressure detector of the head pressure of oil pressure pump unit;
Horsepower based on the discharge flow rate instruction described oil pressure pump unit being sent to horsepower restriction limits rear flow instruction and exports the parallel feedforward compensator of the offset for compensating the head pressure detected by described pressure detector;
Head pressure after compensating based on the offset exported by described parallel feedforward compensator and the horsepower limits value of described oil pressure pump unit that presets and calculate the flow restriction value calculating part of the limits value of the discharge flow rate of described oil pressure pump unit; With
Based on the flow restriction value calculated by described flow restriction value calculating part and the flow instruction of discharge flow rate controlling described oil pressure pump unit, export flow instruction after described horsepower restriction the constrictor of described oil pressure pump unit to.
2. according to claim 1 horsepower of restricting means, is characterized in that, described parallel feedforward compensator is made up of any one in constant gain and band-pass filter or both.
3. according to claim 1 and 2 horsepower of restricting means, is characterized in that, the input to described parallel feedforward compensator from the flow instruction to described oil pressure pump unit, deducts the flow instruction value that comes from operator and forms.
4. a horsepower method for limiting, possesses:
Detect the head pressure of oil pressure pump unit;
The offset that horsepower based on the discharge flow rate instruction described oil pressure pump unit being sent to horsepower restriction limits rear flow instruction and exports for compensating detected described head pressure;
Head pressure after compensating based on the described offset by exporting and the horsepower limits value of described oil pressure pump unit that presets and calculate the limits value of the discharge flow rate of described oil pressure pump unit; With
Based on the described flow restriction value calculated and the flow instruction of discharge flow rate controlling described oil pressure pump unit, export flow instruction after described horsepower restriction to described oil pressure pump unit.
5. according to claim 4 horsepower of method for limiting, is characterized in that, the output of described offset is that the parallel feedforward compensator by being made up of any one in constant gain and band-pass filter or both exports.
6. according to claim 5 horsepower of method for limiting, is characterized in that, the input to described parallel feedforward compensator is from the flow instruction to described oil pressure pump unit, deduct the flow instruction value coming from operator.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012-145684 | 2012-06-28 | ||
| JP2012145684A JP5948165B2 (en) | 2012-06-28 | 2012-06-28 | Horsepower limiting device and horsepower limiting method |
| PCT/JP2013/003825 WO2014002435A1 (en) | 2012-06-28 | 2013-06-19 | Horsepower limiting device and horsepower limiting method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104271950A CN104271950A (en) | 2015-01-07 |
| CN104271950B true CN104271950B (en) | 2016-04-20 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201380022689.1A Expired - Fee Related CN104271950B (en) | 2012-06-28 | 2013-06-19 | Horsepower restricting means and horsepower method for limiting |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP5948165B2 (en) |
| KR (1) | KR101567446B1 (en) |
| CN (1) | CN104271950B (en) |
| WO (1) | WO2014002435A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3190422B1 (en) * | 2016-01-07 | 2018-10-17 | Braun GmbH | Electronic circuit for measuring currents during charging and discharging of a secondary battery |
| US10450726B2 (en) | 2016-09-28 | 2019-10-22 | Hitachi Construction Machinery Co., Ltd. | Pump control system of work machine |
| WO2018061166A1 (en) * | 2016-09-29 | 2018-04-05 | 日立建機株式会社 | Hybrid construction machine |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1119707A (en) * | 1994-09-30 | 1996-04-03 | 三星重工业(株) | Delivery control device for hydraulic pumps and hydraulic systems with such devices |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6192200A (en) * | 1984-10-09 | 1986-05-10 | Mitsubishi Heavy Ind Ltd | Controller of main shaft generator system |
| US5525043A (en) * | 1993-12-23 | 1996-06-11 | Caterpillar Inc. | Hydraulic power control system |
| JPH10177402A (en) * | 1996-12-16 | 1998-06-30 | San Tesuto Kk | Simple adaptive controller |
| JP2001065503A (en) * | 1999-08-27 | 2001-03-16 | Sumitomo Constr Mach Co Ltd | Hydraulic pump control circuit for construction machine |
| US20040062658A1 (en) * | 2002-09-27 | 2004-04-01 | Beck Thomas L. | Control system for progressing cavity pumps |
| KR101648982B1 (en) * | 2009-12-24 | 2016-08-18 | 두산인프라코어 주식회사 | Hydraulic pump control apparatus for construction machinery and hydraulic pump control method for the same |
| CN103003498B (en) * | 2010-07-19 | 2015-08-26 | 沃尔沃建造设备有限公司 | For controlling the system of the hydraulic pump in construction machinery |
-
2012
- 2012-06-28 JP JP2012145684A patent/JP5948165B2/en active Active
-
2013
- 2013-06-19 CN CN201380022689.1A patent/CN104271950B/en not_active Expired - Fee Related
- 2013-06-19 WO PCT/JP2013/003825 patent/WO2014002435A1/en active Application Filing
- 2013-06-19 KR KR1020147018501A patent/KR101567446B1/en active IP Right Grant
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1119707A (en) * | 1994-09-30 | 1996-04-03 | 三星重工业(株) | Delivery control device for hydraulic pumps and hydraulic systems with such devices |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2014009607A (en) | 2014-01-20 |
| WO2014002435A1 (en) | 2014-01-03 |
| JP5948165B2 (en) | 2016-07-06 |
| KR20140100981A (en) | 2014-08-18 |
| KR101567446B1 (en) | 2015-11-11 |
| CN104271950A (en) | 2015-01-07 |
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