CN105971051A - Excavator - Google Patents

Abstract

The invention provides an excavator capable of using high response property to control a hydraulic pump; the excavator comprises the following structures: a bucket rod cylinder (8); the hydraulic pump (14) supplying work oil to the bucket rod cylinder (8); a model prediction control portion (34) used for predicting pumping pressure (Pd) and discharge volume (Vd) after the regulated time according to the telescopic speed (v) of the bucket rod cylinder (8), the pumping pressure (Pd) of the hydraulic pump (14) and the discharge volume (Vd), thus providing the discharge instruction value(Vtc); a controller (30) controlling the hydraulic pump (14). The controller can use the discharge instruction value(Vtc) guided by the model prediction control portion (34) to control the hydraulic pump (14).

Description

Excavator

Technical field

The application advocates based on Japanese patent application 2015-049793 filed in 12 days March in 2015 Number and on March in 2015 13 filed in the priority of Japanese patent application the 2015-051368th. The full content of these Japanese publication is by with reference to being applied in this specification.

The present invention relates to a kind of excavator with hydraulic unit driver.

Background technology

Known a kind of building machinery, prevents engine speed when being steeply risen by the discharge pressure of hydraulic pump Reduce sharply and the sharp increase of the fuel injection amount that causes (with reference to patent documentation 1).

This building machinery carries out a horsepower control, in order to even if the discharge buckling of hydraulic pump, hydraulic pump Pump absorbing torque is also less than engine output torque.Specifically, the discharge at hydraulic pump presses liter In the case of, make output be lowered so that by the pump absorbing torque discharging pressure and the product representation of output Become prescribed torque (high torque).Additionally, be regulation in the rate of climb discharging pressure being judged as hydraulic pump In the case of more than speed, on the basis of making prescribed torque reduce, output is made to be lowered so that pump Absorb the prescribed torque (low moment of torsion) after moment of torsion becomes reduction.It is intended that prevent the row at hydraulic pump The reduction delay of the output that goes out pressure when steeply rising and pump absorbing torque exceedes engine output torque.Knot Really, it is possible to suppress the fuel consumption of waste and the operability of hydraulic unit driver etc. can be improved.

Patent documentation 1: Japanese Unexamined Patent Publication 2005-54903 publication

But, in above-mentioned building machinery, steeply rise in discharge pressure hydraulic pump being detected and make afterwards Its output, reduces this point and does not produces change, and by from making output reduction play discharge compacting border The impact of the time i.e. response time of hydraulic pump required till reduction.Therefore, according to reduction After the setting of prescribed torque (low moment of torsion), it is possible to exceed engine output torque and make the pump of hydraulic pump Absorb moment of torsion increase or there is a possibility that pump absorbing torque excessively reduces.

Summary of the invention

In view of the foregoing, it is desirable to the excavator that can control hydraulic pump with higher response is provided.

The excavator of embodiments of the invention possesses: hydraulic unit driver；The hydraulic pump of variable displacement, upwards State hydraulic unit driver supply working oil；Model Predictive Control portion, state based on above-mentioned hydraulic unit driver Amount and the quantity of state of above-mentioned hydraulic pump, carry out pre-to the quantity of state of the above-mentioned hydraulic pump after the stipulated time Survey and derive the command value for above-mentioned hydraulic pump；And control device, above-mentioned hydraulic pump is controlled System, above-mentioned control device uses the instruction for above-mentioned hydraulic pump that above-mentioned Model Predictive Control portion derives Above-mentioned hydraulic pump is controlled by value.

The effect of invention

By above-mentioned structure, using the teaching of the invention it is possible to provide the excavator of hydraulic pump can be controlled with higher response.

Accompanying drawing explanation

Fig. 1 is the figure of the configuration example of the excavator representing the drive system carrying embodiments of the invention.

Fig. 2 is the synoptic diagram of the configuration example of the drive system representing embodiments of the invention.

Fig. 3 is the negative control line chart representing the relation between pump discharge and negative pressure control.

Fig. 4 is that the horsepower representing the relation between pump discharge and pump discharge pressure controls line chart (PQ line chart).

Fig. 5 is the functional block diagram of the configuration example representing control system.

Fig. 6 is the figure of the time passage representing that pump discharges pressure, discharge capacity and pump absorbing torque.

Fig. 7 is the figure of the configuration example of the excavator representing embodiments of the invention.

Fig. 8 is the loop diagram of the configuration example of the drive system representing that the excavator of Fig. 7 carried.

Fig. 9 is the synoptic diagram of the configuration example representing revolution hydraulic circuit.

Figure 10 is the figure of the relation representing that revolution hydraulic circuit is intrinsic pressure and turning round between decompression flow.

Figure 11 is the figure of the configuration example representing control system.

Figure 12 is to represent pivoted lever operational ton and turn round the figure of the intrinsic pressure time passage of hydraulic circuit.

The explanation of symbol

1: lower traveling body；2: slew gear；2L: left driving hydraulic motor；2R: right side Traveling hydraulic motor；3: upper rotation；4: swing arm；5: dipper；6: scraper bowl；7: swing arm Cylinder；8: dipper cylinder；9: scraper bowl cylinder；11: electromotor；14,14L, 14R: hydraulic pump；15: Control pump；17: control valve；19L, 19R: air relief valve；20L, 20R: negative control choke valve；21: Revolution hydraulic motor；21L: the 1 port；21R: the 2 port；22: operating oil tank；30: Controller；31: Drive Status amount obtaining section；32: pressure test section discharged by pump；33: horsepower controls Portion；34: Model Predictive Control portion；35: model state resets portion；40L, 40R: middle other Siphunculus road；41L, 41R: negative control choke valve；50,50L, 50R: pump control mechanism；51L, 51R: Deflection driver；55L, 55R: electromagnetic valve；60L, 60R: slide-valve gear；61L, 61R: row Discharge control portion；70L, 70R, 73: pipeline；71L, 71R: revolution air relief valve；72L, 72R: Check valve；75: engine speed sets driver plate；80: mechanical brake；81: decelerator；82: Revolution action bars；83: main air relief valve；100: drive system；171L、171R、172L、172R、 173L, 173R, 174R, 175L, 175R: control valve；200: revolution hydraulic circuit；E30: Attitude detecting portion；E31: discharge capacity test section；E32: the revolution intrinsic pressure test section of hydraulic circuit；E33: Angle of revolution speed detecting portion；P1: the 1 port；P2: the 2 port；S1～S6, S7L, S7R: Pressure transducer.

Detailed description of the invention

Hereinafter, referring to the drawings the preferred embodiments of the present invention are illustrated.Fig. 1 is denoted as this The configuration example of the excavator of the building machinery of bright embodiment.The excavator of Fig. 1 is, caterpillar Via slew gear 2 to carry top revolution in the way of X-axis revolution freely on lower traveling body 1 Body 3.Additionally, upper rotation 3 possesses excavation auxiliary equipment in central front portion.Excavate auxiliary equipment Including swing arm 4, dipper 5 and scraper bowl 6 as work body, and include as hydraulic unit driver Swing arm cylinder 7, dipper cylinder 8 and scraper bowl cylinder 9.

Additionally, be provided with, at swing arm cylinder 7, the swing arm stroke that the retracted position to swing arm cylinder 7 detects Sensor 7s.Additionally, be provided with, at dipper cylinder 8, the bucket that the retracted position to dipper cylinder 8 detects Throw of lever sensor 8s, is provided with, at scraper bowl cylinder 9, the shovel that the retracted position to scraper bowl cylinder 9 detects Bucket stroke sensor 9s.Alternatively, it is also possible to pass by the angle that the rotational angle of work body is detected Sensor replaces at least one in stroke sensor.

Fig. 2 is the synoptic diagram of the drive system 100 of embodiments of the invention.Drive system 100 is main Including electromotor 11, hydraulic pump 14, control valve 17 and controller 30.

Hydraulic pump 14 is driven by electromotor 11.In the present embodiment, hydraulic pump 14 is to make every 1 to rotate Output (discharge capacity) become variable variable type diagram plate type hydraulic pump.Discharge capacity is controlled by pump control mechanism 50. Specifically, hydraulic pump 14 includes hydraulic pump 14L, the Yi Jiyou being controlled discharge capacity by pump control mechanism 50L Pump control mechanism 50R controls the hydraulic pump 14R of discharge capacity.Additionally, in the present embodiment, hydraulic pump 14 The rotary shaft of rotary shaft and electromotor 11 link and with the rotation identical with the rotary speed of electromotor 11 Speed rotates.It addition, the rotary shaft of hydraulic pump 14 links with flywheel, suppression electromotor output is turned round The variation of rotary speed during square variation.

Electromotor 11 is the driving source of excavator.In the present embodiment, electromotor 11 is to possess conduct The turbocharger of supercharger and the Diesel engine of fuel injection device, be equipped on upper rotation 3.It addition, electromotor 11 can also possess mechanical supercharger as supercharger.

Control valve 17 is the hydraulic pressure that the working oil discharged by hydraulic pump 14 supplies towards various hydraulic unit drivers Controlling organization.In the present embodiment, control valve 17 include control valve 171L, 171R, 172L, 172R, 173L、173R、174R、175L、175R.Additionally, hydraulic unit driver includes left driving hydraulic pressure Motor 2L, right travel hydraulic motor 2R, swing arm cylinder 7, dipper cylinder 8, scraper bowl cylinder 9, revolution With hydraulic motor 21.

Specifically, hydraulic pump 14L make working oil via connection control valve 171L, 172L, 173L, And the intermediate bypass pipeline 40L of 175L is recycled to operating oil tank 22.Equally, hydraulic pump 14R makes Working oil is via connection control valve 171R, the intermediate bypass of 172R, 173R, 174R and 175R Pipeline 40R is recycled to operating oil tank 22.

Control valve 171L is to the working oil between left driving hydraulic motor 2L and hydraulic pump 14L Flow and the guiding valve that is controlled of flow direction.

Control valve 171R is as the guiding valve travelling straight travel valve.The stream of control valve 171R switch operating oil Dynamic, in order in order to improve the craspedodrome of lower traveling body 1 and from hydraulic pump 14L towards left driving liquid Pressure motor 2L and right travel hydraulic motor 2R is supplied respectively to working oil.Specifically, on a left side Skidding is sailed by hydraulic motor 2L and right travel hydraulic motor 2R and other arbitrary hydraulic-driven In the case of device is simultaneously operated, hydraulic pump 14L is towards left driving hydraulic motor 2L and right side row Sail and supply working oil with the both sides of hydraulic motor 2R.It addition, in the case of in addition, hydraulic pump 14L supplies working oil towards left driving hydraulic motor 2L, and hydraulic pump 14R is towards right travel hydraulic pressure Motor 2R supplies working oil.

Control valve 172L is the stream to the working oil between revolution hydraulic motor 21 and hydraulic pump 14L The guiding valve that amount and flow direction are controlled.

Control valve 172R to right travel with between hydraulic motor 2R and hydraulic pump 14L, 14R The guiding valve that the flow of working oil and flow direction are controlled.

Control valve 173L, 173R are to the work between swing arm cylinder 7 and hydraulic pump 14L, 14R respectively The guiding valve that the flow of oil and flow direction are controlled.It addition, control valve 173R is as operation dress The swing arm action bars put works in the case of being operated, control valve 173L at swing arm action bars by towards swing arm Direction of improvement works in the case of operating more than the bar operational ton of regulation.

Control valve 174R is the flow to the working oil between hydraulic pump 14R and scraper bowl cylinder 9 and stream The guiding valve that dynamic direction is controlled.

Control valve 175L, 175R are to the work between dipper cylinder 8 and hydraulic pump 14L, 14R respectively The guiding valve that the flow of oil and flow direction are controlled.It addition, control valve 175L is as operation dress The dipper action bars put works in the case of being operated, and control valve 175R is operated at dipper action bars Work in the case of more than the bar operational ton of regulation.

Intermediate bypass pipeline 40L, 40R are being in control valve 175L of most downstream, 175R and work respectively Make between fuel tank 22, possess negative control choke valve 41L, 41R.Hereinafter, by negative control (negative control) Referred to as " negative control ".Negative control choke valve 41L, 41R are to the working oil that hydraulic pump 14L, 14R discharge Flowing limits, and thus produces negative pressure control in the upstream of negative control choke valve 41L, 41R.

Air relief valve 19L, 19R are the valves that negative pressure control is limited to below the decompressed pressure of regulation.At this In embodiment, air relief valve 19L, 19R throttle with negative control respectively on intermediate bypass pipeline 40L, 40R Valve 41L, 41R are connected in parallel.

Controller 30 is the functional imperative being controlled excavator, e.g. possess CPU, RAM, The computer of ROM, NVRAM etc..

In the present embodiment, controller 30 output based on guide's pressure sensor (not shown) is to various behaviour The operation content (such as, the presence or absence of bar operation, bar direction of operating, bar operational ton etc.) making device carries out electricity Detection.Guide's pressure sensor is to operating the various operation dress such as dipper action bars, swing arm action bars One example in the operation content detection portion that the guide's pressure produced in the case of putting is measured.But, operation Content detection portion can also use the inclination sensor that the inclination to various action bars detects etc., first Sensor beyond pilot sensor is constituted.

Additionally, the work that controller 30 output based on pressure transducer S1～S4 is to various hydraulic unit drivers Electro-detection is carried out as situation.

The negative pressure control produced in the upstream of negative control choke valve 41L, 41R is entered by pressure transducer S1, S2 Row detection, and the value detected is born the output of pressure control signal to controller 30 as electricity.

The discharge pressure of hydraulic pump 14L, 14R is detected by pressure transducer S3, S4, and will detection The value arrived is discharged pressure signal as electricity and is exported to controller 30.

Engine speed sets the driver plate that driver plate 75 is the rotating speed for setting electromotor, such as, be arranged on So that operator can be according to multiple stage switching engine rotating speeds in driver's cabin.

Further, controller 30 makes CPU according to the operation content of various operation devices and various hydraulic pressure The working condition of driver performs the program corresponding with various functional imperative.

Then, illustrate that controller 30 controls the output of hydraulic pump 14 according to negative pressure control with reference to Fig. 3 Process.It addition, Fig. 3 is that the output (hereinafter referred to as " pump discharge ") representing hydraulic pump 14 is with negative The negative control line chart of the relation between pressure control, the longitudinal axis represents that pump discharge, transverse axis represent negative pressure control.

In the present embodiment, controller 30 makes to increase and decrease for the control electric current of pump control mechanism 50L and make liquid The swash plate deflection angle increase and decrease of press pump 14L, thus makes the discharge capacity of hydraulic pump 14L increase and decrease.Such as, control Device 30 is that negative pressure control is the lowest, makes control electric current more increase and make the discharge capacity of hydraulic pump 14L more increase. In the following, the discharge capacity of hydraulic pump 14L is illustrated, but for the discharge capacity of hydraulic pump 14R It is also suitable same explanation.

Specifically, the working oil that hydraulic pump 14L discharges, arrived by intermediate bypass pipeline 40L Negative control choke valve 41L, produces negative pressure control in the upstream of negative control choke valve 41L.

Such as, when in order to make dipper cylinder 8 work and control valve 175L work time, hydraulic pump 14L discharge Working oil via control valve 175L flow into dipper cylinder 8.Therefore, the amount of negative control choke valve 41L is arrived Reducing or disappear, the negative pressure control produced in the upstream of negative control choke valve 41L reduces.

Controller 30, according to the reduction of the negative pressure control detected by pressure transducer S1, makes to adjust for pump The control electric current of joint device 50L increases.Pump control mechanism 50L is according to the control electric current from controller 30 Increase, make the swash plate deflection angle of hydraulic pump 14L increase and make discharge capacity increase.As a result, towards dipper cylinder 8 The working oil that supply is sufficient, dipper cylinder 8 is appropriately driven.

Afterwards, when in order to make the work stopping of dipper cylinder 8 and time control valve 175L returns to neutral position, The working oil that hydraulic pump 14L discharges does not flows into dipper cylinder 8 and arrives negative control choke valve 41L.Therefore, The amount arriving negative control choke valve 41L increases, and the negative pressure control produced in the upstream of negative control choke valve 41L increases Greatly.

Controller 30, according to the increase of the negative pressure control detected by pressure transducer S1, makes to adjust for pump The control current reduction of joint device 50L.Pump control mechanism 50L is according to the control electric current from controller 30 Reduce, make the swash plate deflection angle of hydraulic pump 14L reduce and make discharge capacity reduce.As a result, pump discharge reduces, The working oil that hydraulic pump 14L discharges is obtained by the pressure loss (pumping loss) during intermediate bypass pipeline 40L To suppression.

Pump control line indicated by the solid line represents along with negative pressure control reduces and the tendency of pump discharge increase.? Hereinafter, the control of pump discharge based on negative pressure control as described above is referred to as " negative control ".By negative control System, drive system 100 can suppress the energy of waste under the holding state not making hydraulic unit driver work Amount consumes.Its reason is, it is possible to pumping loss produced by the working oil that suppression hydraulic pump 14 is discharged. Additionally, drive system 100 is in the case of making hydraulic unit driver work, it is possible to from hydraulic pump 14 towards liquid Sufficient working oil required for pressure driver supply.Fig. 3 eliminate negative pressure control under holding state with The diagram of the relation between pump discharge, but actually, in the standby state at negative pressure control less than regulation In the case of pressure, pump discharge is limited in minimum discharge.

Additionally, drive system 100 and negative control are performed in parallel a horsepower control.Horsepower controls, root Pump discharge is made to reduce according to the rising of discharge pressure (hereinafter referred to as " pump discharge pressure ") of hydraulic pump 14.Its Purpose is, in order to prevent the generation of moment of torsion.That is, it is intended that in order to make by pump discharge pressure With the output that the absorbed horsepower (pump absorbing torque) of the hydraulic pump of the product representation of pump discharge is less than electromotor Horsepower (engine output torque).

Fig. 4 is that the horsepower representing the relation between pump discharge and pump discharge pressure controls line chart (PQ line chart), The longitudinal axis is pump discharge, and transverse axis is that pressure discharged by pump.Horsepower control line represents along with pump discharge pressure reduces and pump The tendency that flow increases.Additionally, determine a horsepower control line, target according to target pump absorbing torque Tt Pump absorbing torque Tt is the biggest, then horsepower control line more offsets towards the upper right side of figure.Fig. 4 expression solid line Represent the target pump absorbing torque Tt1 corresponding with horsepower control line more than be represented by dashed line with horsepower The situation of the target pump absorbing torque Tt2 that control line is corresponding.It addition, target pump absorbing torque Tt is to make The permission maximum of the pump absorbing torque that can utilize for hydraulic pump 14 and value set in advance.In this reality Executing in example, target pump absorbing torque Tt is redefined for fixed value but it also may be variable value.

In the present embodiment, controller 30 is, makes hydraulic pump 14L with target pump absorbing torque Tt In the case of action, it is controlled according to the discharge capacity of the horsepower control pair hydraulic pump 14L shown in Fig. 4. Specifically, derive according to the pump discharge discharging pressure corresponding with the i.e. pump of the detected value of pressure transducer S3 Target discharge capacity.Then, the control electric current corresponding with target discharge capacity is exported to pump control mechanism by controller 30 50L.Pump control mechanism 50L makes the increase and decrease of swash plate deflection angle make discharge capacity become target row according to this control electric current Amount.By the feedback control of this pump absorbing torque, even if because the load relevant to hydraulic unit driver becomes Moving and make pump discharge buckling and move, controller 30 also is able to make hydraulic pump 14L with target pump absorbing torque Tt action.Also it is same for hydraulic pump 14R.

But, as long as utilizing this feedback control, controller 30 just cannot eliminate from detecting that pump is discharged Response time required till actually making pump discharge change is played in the change of pressure.

Therefore, controller 30 uses Model Predictive Control to eliminate this response time.At this In embodiment, controller 30 quantity of state based on hydraulic unit driver and the quantity of state pair of hydraulic pump 14 The quantity of state of the hydraulic pump 14 after the stipulated time is predicted and derives the command value for hydraulic pump 14. The quantity of state of hydraulic unit driver is that the reaction for the load change relevant to hydraulic unit driver is discharged than pump Press fast quantity of state, the stretching speed comprising the hydraulic cylinder as hydraulic unit driver, pass through hydraulic-driven Device and the rotational angular velocity etc. of job factor that rotates.The quantity of state of hydraulic pump 14 comprise pump discharge pressure, Discharge capacity, swash plate deflection angle etc..The quantity of state of the hydraulic pump 14 after the stipulated time is the object becoming prediction Quantity of state, comprise pump and discharge pressure etc..Additionally, the command value for hydraulic pump 14 comprises discharge capacity instruction Value etc..

Herein, with reference to Fig. 5, the configuration example of control system used when performing Model Predictive Control is entered Row explanation.It addition, Fig. 5 is the functional block diagram of the configuration example representing control system.

Specifically, the control system of Fig. 5 includes controller 30, Drive Status amount obtaining section 31 And pump discharge pressure test section 32.Additionally, controller 30 includes horsepower control portion 33, model prediction Control portion 34 and model state reset portion 35.

Drive Status amount obtaining section 31 is the functional imperative of the quantity of state obtaining hydraulic unit driver, such as Including the displacement transducer that the retracted position of the hydraulic cylinder as hydraulic unit driver is detected.Displacement Sensor obtains the stretching speed v of hydraulic cylinder based on the displacement detected, using this value as the flexible speed of electricity Degree signal exports to Model Predictive Control portion 34.In the present embodiment, displacement transducer includes swing arm row Journey sensor 7s, dipper stroke sensor 8s and scraper bowl stroke sensor 9s.It addition, driver shape State amount obtaining section 31 can also be the angular transducer that the rotational angle to work body detects.At this In the case of too, Drive Status amount obtaining section 31 obtains hydraulic cylinder based on the angle detected Stretching speed v, exports this value to Model Predictive Control portion 34 as electricity stretching speed signal.

Pressure test section 32 discharged by pump is that pump is discharged the functional imperative that pressure detects.In the present embodiment, Pressure test section 32 discharged by pump is that pump is discharged pressure transducer S3, S4 that pressure Pd detects.Pressure Detected value is discharged pressure signal as electric pump and is exported to Model Predictive Control portion 34 by sensor S3, S4.

Horsepower control portion 33 is the function that the absorbed horsepower (pump absorbing torque) to hydraulic pump 14 is controlled Key element.In the present embodiment, horsepower control portion 33 is by the control electric current output corresponding with discharge capacity command value To pump control mechanism 50, the pump discharge of hydraulic pump 14 is controlled, thus pump absorbing torque is carried out Control.

Model Predictive Control portion 34 is to use to return the hydraulic pressure including hydraulic unit driver and hydraulic pump 14 Model that the movement on road is predicted, carry out control (model prediction based on the theory of optimal control in real time Control) functional imperative.The Model Predictive Control of hydraulic circuit is the use of the object model of hydraulic circuit The control of (plant model).Additionally, the object model of hydraulic circuit is defeated according to for hydraulic circuit Enter to derive the model of the output of hydraulic circuit.In the present embodiment, Model Predictive Control portion 34 can Pressure Pd, the stretching speed v of hydraulic cylinder, discharge capacity Vd of hydraulic pump 14L and discharge capacity is discharged according to pump The minor variations Δ Vt of command value, the predictive value of pressure discharged by the pump deriving the future in finite time.Separately Outward, stretching speed v comprises the rate of stretch of swing arm cylinder 7, the rate of stretch of dipper cylinder 8, scraper bowl cylinder 9 Stretching speed etc..Additionally, minor variations Δ Vt is the discharge capacity command value Vt row with last time again of last time The difference of amount command value Vtp.Additionally, discharge capacity Vd is, will be with discharge capacity command value from horsepower control portion 33 The moment that pump control mechanism 50 exports is risen and somewhat postpones and reach to instruct with this discharge capacity by corresponding control electric current The value that value is corresponding.Therefore, discharge capacity Vd is derived according to the passage in the past of discharge capacity command value.Such as, Discharge capacity command value cross over specified time limit indeclinable in the case of, current discharge capacity Vd becomes and this discharge capacity The value that command value is identical.Additionally, in discharge capacity command value in the case of there occurs change recently, use Discharge capacity command value before change, the discharge capacity command value after change and the time constant of time lag of first order, come Calculate current discharge capacity Vd.

It is in the object model used in Model Predictive Control portion 34 that model state resets portion 35 The functional imperative of variation coefficient constant.In the present embodiment, model state resets portion 35 and makes Discharge capacity command value Vt as variation coefficient becomes the function f (Pd) of pump discharge pressure Pd, and exports and make Pressure Pd corresponding discharge capacity command value Vt (=f (Pd)=2 π × Tt/Pd) discharged by pump for input.In more detail, Model state resets the horsepower control line under portion 35 controls with reference to horsepower, derives and discharges pressure with pump Discharge capacity command value Vt corresponding for Pd.That is, the long-pending divided by 2 π of pressure Pd and discharge capacity command value Vt is discharged with pump And the value obtained becomes the mode of target pump absorbing torque Tt, derives and discharge row corresponding to pressure Pd with pump Amount command value Vt.

Then, to the meter performed in resetting portion 35 in Model Predictive Control portion 34 and model state Illustrate.Model Predictive Control portion 34 uses the following matrix side of the state representing hydraulic circuit Journey derives pump and discharges the predictive value of pressure.It addition, A, B are the constructional features representing hydraulic circuit Coefficient matrix, v₁、v₂、……、v_nIt is n the respective stretching speed of hydraulic cylinder.Additionally, coefficient Matrix A comprises above-mentioned function f as component, the multiplying of f Yu Pd in this matrix equation, Mean that pump is discharged pressure Pd resets portion 35 as independent variable to calculate function f, i.e. model state Discharge pressure Pd based on pump and carry out calculated pump rate command value Vt.Further, coefficient matrices A is wrapped as component The ratio of the rotating speed containing hydraulic pump 14 and cylinder volume and the inverse of the time constant of expression pump operating lag (1/T), this in this matrix equation means the pressure to working oil than the multiplying with discharge capacity Vd Change calculates, and this inverse means to enter the change in volume of working oil with the multiplying of discharge capacity Vd Row calculates.Additionally, coefficient matrix B comprises the pressurized of n the respective piston of hydraulic cylinder as component Ratio (the RA of area RA and cylinder volume RV₁/RV₁、RA₂/RV₂、……、RA_n/RV_n), this matrix Ratio RA in equation_n/RV_nWith stretching speed v_nMultiplying, it is meant that Model Predictive Control portion 34 Calculate being changed by the pressure of the flexible working oil caused of the n-th hydraulic cylinder.Additionally, coefficient Matrix B comprises the inverse (1/T) of the time constant of the operating lag representing pump, this matrix as component This inverse in equation and the multiplying of minor variations Δ Vt, it is meant that Model Predictive Control portion 34 Calculate by the change in volume of the flexible working oil caused of n hydraulic cylinder.

[numerical expression 1]

$\frac{d}{dt}\left[\begin{array}{c}Pd\\ Vd\end{array}\right]=A\left[\begin{array}{c}Pd\\ Vd\end{array}\right]+B\left[\begin{array}{c}{v}_1\\ v_2\\ .\\ .\\ .\\ v_n\\ \mathrm{\Δ}Vt\end{array}\right]$

More specifically, Model Predictive Control portion 34 by from pump discharge pressure test section 32 accept current The pump in moment is discharged pressure Pd input and is reset portion 35 to model state and again set from model state Determine portion 35 and accept discharge capacity command value Vt.Additionally, Model Predictive Control portion 34 pump based on current time Discharge pressure Pd, discharge capacity Vd, n hydraulic cylinder respective stretching speed v₁～v_n, discharge capacity command value micro- Little changes delta Vt and above-mentioned matrix equation, derive pump discharge pressure Pd and discharge capacity Vd is respective micro- Score value.Then, the pump of current time is discharged pressure Pd to be added with its differential value and derive 1 and control week The predictive value Pd ' of pressure discharged by the pump of after date.Discharge capacity Vd is derived similarly to 1 and control week after date The predictive value Vd ' of discharge capacity.It addition, discharge capacity Vd of current time be that time lag of first order is accounted for and The value that discharge capacity command value Vt according to the past calculates.

Afterwards, predictive value Pd ' input is reset portion 35 to model state by Model Predictive Control portion 34. Model state resets portion 35 and uses predictive value Pd ' and horsepower control line chart to carry out calculated pump rate instruction Value Vt '.Then, Model Predictive Control portion 34 Acceptance Model state resets the row that portion 35 calculates Amount command value Vt '.Additionally, n hydraulic cylinder based on predictive value Pd ' and Vd ', current time is each From stretching speed v₁～v_n, the minor variations Δ Vt of discharge capacity command value and above-mentioned matrix equation, lead Go out the respective differential value of predictive value Pd ' and Vd '.Then, predictive value Pd ' is added with its differential value And derive 2 pumps controlling week after date and discharge the predictive value Pd of pressure ".For predictive value Vd ' similarly Derive 2 predictive value Vd controlling week after date ".

So, Model Predictive Control portion 34 derives and employs the situation of minor variations Δ Vt constantly (i.e., Discharge capacity command value is the situation of each changes delta Vt according to each control cycle) under n control week after date Pump discharge pressure and the respective predictive value of discharge capacity.

Further, Model Predictive Control portion 34 is derived by said method and crosses over n control cycle and continue Employ the n in the case of the value of the multiple minor variations set on the basis of minor variations Δ Vt The individual pump controlling week after date discharges pressure and the respective predictive value of discharge capacity.Such as, by by minor variations Δ Vt is added with setting or deducts setting from minor variations Δ Vt, derives multiple minor variations Each of value.

On this basis, Model Predictive Control portion 34 selects to make model shape from the value of multiple minor variations State resets portion 35 and derives based on n the pump discharge pressure controlling week after date (such as 10 control week after date) Discharge capacity command value and n the difference of discharge capacity controlling week after date become the minor variations Δ Vtc of minimum.Tool For body, select in the value of the multiple minor variations comprising minor variations Δ Vt, as current The minor variations Δ Vtc that should use.

Then, Model Predictive Control portion 34 by selected minor variations Δ Vtc to horsepower control portion 33 Output.Horsepower control portion 33 uses the minor variations Δ Vtc that Model Predictive Control portion 34 selects, and passes through The discharge capacity of hydraulic pump 14 is controlled by Model Predictive Control.

So, Model Predictive Control portion 34 is according to each control cycle, to employing multiple minor variations Value each in the case of n control week after date pump discharge pressure and the predictive value of discharge capacity is carried out Calculate.Then, select to make model state reset portion 35 to discharge based on n the pump controlling week after date The discharge capacity command value that pressure derives and the difference of n the discharge capacity controlling week after date become minimum minor variations ΔVtc.Horsepower control portion 33, according to each control cycle, selects according to Model Predictive Control portion 34 Minor variations Δ Vtc calculates discharge capacity command value Vtc that should use specifically, and will instruct with this discharge capacity Control electric current corresponding for value Vtc exports to pump control mechanism 50.It addition, horsepower control portion 33 such as passes through Discharge capacity command value Vt of last time is calculated, with minor variations Δ Vtc phase Calais, the discharge capacity that should use specifically Command value Vtc.The swash plate deflection angle of hydraulic pump 14 is changed to control electric current phase with it by pump control mechanism 50 The angle answered.As a result, discharge capacity Vd of hydraulic pump 14 is increased and decreased to producing target pump absorbing torque Tt Discharge capacity.

Then, with reference to Fig. 6 to excavating load in including the execution of dredge operation of dipper closed procedure Pump during sharp increase is discharged the time passage of pressure, discharge capacity and pump absorbing torque and is illustrated.It addition, Fig. 6 It it is the figure of the time passage representing that pump discharges pressure, discharge capacity and pump absorbing torque.Additionally, the void of Fig. 6 Line represents the time passage being provided without in the case of Model Predictive Control, and solid line represents that to have employed model pre- Time passage in the case of observing and controlling system.Additionally, controlled by horsepower in the execution of this dredge operation Control hydraulic pump 14.

In the case of being provided without Model Predictive Control, when excavating load sharp increase at moment t1, pump is arranged Go out to press Pd and pump absorbing torque Tp to start to increase.Its reason is, although due to hydraulic pump 14 Operating lag and tieed up from hydraulic pump 14 towards the flow of the working oil of dipper cylinder 8 within one period of period Hold, but the rate of stretch of dipper cylinder 8 is also slowed down.

Specifically, pump absorbing torque Tp after increasing with exceeding target pump absorbing torque Tt time Carve t2 and transfer minimizing to, afterwards, after being reduced below target pump absorbing torque Tt at moment t3 again Secondary transfer increase to.Afterwards, pump absorbing torque Tp is repeated increasing at surrounding target pump absorbing torque Tt Restrain to target pump absorbing torque Tt while subtracting.

So, controller 30, when comprising operating lag, discharges the variation of pressure Pd according to pump Make discharge capacity command value increase and decrease, by feedback control, discharge capacity Vd is controlled such that pump absorbing torque Tp Become target pump absorbing torque Tt.Therefore, pump absorbing torque Tp can temporarily exceed target pump absorbing torque Tt, according to circumstances difference pump absorbing torque Tp sometimes can exceed engine output torque.On the contrary, make The pump absorbing torque Tp having exceeded target pump absorbing torque Tt returns to the level of target pump absorbing torque Tt Hui Shi, makes pump absorbing torque Tp exceedingly be reduced to significantly less than target pump absorbing torque sometimes The level of Tt.

On the other hand, in the case of have employed Model Predictive Control, with the control system not using Fig. 5 The situation of system is different, and pump absorbing torque Tp will not exceed target pump absorbing torque Tt but dimension significantly Hold target pump absorbing torque Tt to elapse unchangeably.Its reason is, by Model Predictive Control in pumping Change discharge capacity command value before receiving torque T p breakaway pump absorbing torque Tt and prophylactically suppress pump Absorb the disengaging of torque T p.

Specifically, controller 30 pump based on current time discharges pressure Pd, discharge capacity Vd, dipper cylinder The stretching speed of 8 and above-mentioned matrix equation, to the regulation that have employed in the case of various discharge capacity command value Pressure discharged by pump after time and discharge capacity is predicted.It addition, the stretching speed of dipper cylinder 8 be for The length change of the fast i.e. dipper cylinder 8 of quantity of state of pressure is discharged in the reaction of the variation excavating load than pump.Cause This, at current time, although the rate of stretch of dipper cylinder 8 is the most decreased, but the pump of hydraulic pump 14 row Go out pressure also not rise.

And, controller 30 discharges the predictive value of pressure based on the pump after the stipulated time, derives and makes model shape The difference of predictive value of discharge capacity after state resets discharge capacity command value and the stipulated time that portion 35 derives becomes Minimum discharge capacity command value.Then, use this discharge capacity command value that the pump discharge of hydraulic pump 14 is controlled System, and maintain pump absorbing torque Tp according to target pump absorbing torque Tt.

So, discharge capacity Vd is controlled by controller 30 by Model Predictive Control, so that discharge capacity refers to Make value increase and decrease, and become target pump absorbing torque Tt.Therefore, even if excavating the situation that load increases severely Under, it is also possible to suppress or prevent pump absorbing torque Tp from temporarily exceeding target pump absorbing torque Tt, and energy Enough suppress or prevent pump absorbing torque Tp from exceeding engine output torque.

Additionally, the control system of Fig. 5 is compared with the feedback control of the pump discharge discharging pressure based on pump, energy Enough impacts of the operating lag of reduction hydraulic pump 14 variation on excavating load.

Then, the excavator of the scope that can expand the rotary torque that can utilize is illustrated.

In the past, it is known that a kind of excavator, two were used as the revolution air relief valve of revolution hydraulic motor Level air relief valve adjusts rotary torque (for example, referring to Japanese Unexamined Patent Publication 6-17447 publication).

This excavator is, will turn round decompressed pressure when increasing the motor capacity of revolution hydraulic motor It is set as step down side or when reducing the motor capacity of revolution hydraulic motor by revolution decompression pressure On the basis of power is set as step-up side, while discharging working oil from two-stage decompression valve, make revolution liquid Pressure motor rotates.And, carry out the situation of low speed revolution and carry out the both sides of situation about turning round at a high speed, Making rotary torque is same degree.

But, above-mentioned excavator will not be by the pressure of the revolution decompressed pressure of not enough two-stage decompression valve Revolution hydraulic motor is controlled by working oil.Therefore, it is possible to the size quilt of the rotary torque utilized It is limited to narrower scope.

In view of the foregoing, it is desirable to the scope of the size that can expand the rotary torque that can utilize is provided Excavator.

Hereinafter, referring to the drawings the excavator of the scope that can expand the rotary torque that can utilize is carried out Explanation.The excavator of Fig. 7 possesses slew gear 2 on caterpillar lower traveling body 1.Additionally, return Rotation mechanism 2 is to carry upper rotation 3 in the way of X-axis revolution freely.

Additionally, the example that upper rotation 3 possesses auxiliary equipment in central front portion i.e. excavates attached dress Put.Excavate auxiliary equipment and include swing arm 4, dipper 5 and scraper bowl 6, and include as hydraulic unit driver Swing arm cylinder 7, dipper cylinder 8 and scraper bowl cylinder 9.

Attitute detecting device M1 includes swing arm angular transducer, dipper angular transducer, scraper bowl angle Sensor and body sway sensor.Swing arm angular transducer is the sensor obtaining swing arm angle, Such as include the anglec of rotation sensing that the anglec of rotation of swing arm foot pin (boom foot pin) is detected Stroke sensor that device, path increment to swing arm cylinder 7 detect, angle of inclination to swing arm 4 are entered Inclination (acceleration) sensor etc. of row detection.Dipper angular transducer is the sensing obtaining dipper angle Device, such as, include the angular sensor detecting the anglec of rotation of dipper connecting pin, to bucket Stroke sensor that the path increment of bar cylinder 8 carries out detecting, angle of inclination to dipper 5 are detected Tilt (acceleration) sensor etc..Scraper bowl angular transducer is the sensor obtaining scraper bowl angle, such as, wrap Include angular sensor that the anglec of rotation to scraper bowl connecting pin detects, row to scraper bowl cylinder 9 The inclination (acceleration) that stroke sensor that journey amount carries out detecting, angle of inclination to scraper bowl 6 are detected Sensor etc..Body sway sensor is the sensor obtaining fuselage angle of inclination, such as, include 2 axles Tilt (acceleration) sensor etc..

Fig. 8 is the loop diagram of the configuration example of the drive system 100 representing that the excavator of Fig. 7 carried. Drive system 100 have driven by driving source such as electromotor, electro-motor (not shown) hydraulic pump 14L, 14R.Following, sometimes hydraulic pump 14L, 14R are referred to as " hydraulic pump 14 ".For by left and right Other elements constituted for a pair are also same.Hydraulic pump 14 is to make every 1 discharge capacity rotated (cc/rev) hydraulic pump of variable variable displacement is become.Additionally, hydraulic pump 14L makes working oil via connection Control valve 171L, the intermediate bypass pipeline 40L of 172L, 173L and 175L are recycled to operating oil tank 22.Equally, hydraulic pump 14R makes working solution via connection control valve 171R, 172R, 174R, 173R And the intermediate bypass pipeline 40R of 175R is recycled to operating oil tank 22.

In the example of fig. 8, controller 30 makes CPU perform and the operation according to various operation devices Content makes the program that the various functional imperative of the actions such as electromagnetic valve 55L, 55R are corresponding.

Electromagnetic valve 55L, 55R are the instructions and the valve of action exported according to controller 30.In this enforcement In example, electromagnetic valve 55L, 55R are that the current-order according to controller 30 output is to from controlling pump 15 The control imported towards compression chamber 612L, 612R of output control portion 61L, 61R is pressed into Row sum-equal matrix Electromagnetic relief pressure valve.

Pump control mechanism 50L is the drive mechanism being controlled the output to hydraulic pump 14L, mainly wraps Include deflection driver 51L, slide-valve gear 60L, output control portion 61L and feedback rod 62L.

Deflection driver 51L is to the swash plate (bar) for making the discharge capacity of hydraulic pump 14L (pump capacity) change Carry out the functional imperative of deflection driven.Specifically, deflection driver 51L includes: at one end have Big footpath compression zone PR1 and there is the working piston 510L of path compression zone PR2 at the other end；With greatly The compression chamber 511L that footpath compression zone PR1 is corresponding；And the compression chamber corresponding with path compression zone PR2 512L.Import the discharge pressure of hydraulic pump 14L towards compression chamber 511L via guiding valve 600L, or from being subject to Pressure chamber 511L discharges working oil via guiding valve 600L.Additionally, import hydraulic pump towards compression chamber 512L The discharge pressure of 14L.Working piston 510L is, present dynasty compression chamber 511L import working oil and towards pressurized During the displacement of 512L side, room, by the swash plate (bar) of hydraulic pump 14L towards low discharge side deflection driven.Additionally, Working piston 510L is, when from compression chamber 511L discharge working oil and towards compression chamber 511L side displacement Time, by the swash plate (bar) of hydraulic pump 14L towards big flow side deflection driven.

Slide-valve gear 60L is the function of the supply and discharge for being operated oil relative to deflection driver 51L Key element, including guiding valve 600L and spring 601L.Guiding valve 600L has the row importing hydraulic pump 14L Go out pressure the second port of connect with operating oil tank 22 of the first port and with compression chamber 511L company Logical output port.Furthermore it is possible to optionally switch to guiding valve 600L connect the first port with defeated Go out the primary importance of port, connect the second port and the second position of output port or the first port And second neutral position that do not connect with output port of port.Guiding valve 600L is composed by spring 601L Give along making its power to the effect of the direction of second position displacement.

Output control portion 61L is the functional imperative for making guiding valve 600L displacement.Specifically, row Discharge control portion 61L includes servo piston 610L, spring 611L and compression chamber 612L.Servo is lived Plug 610L presses according to the control that electromagnetic valve 55L generates and court makes guiding valve 600L to primary importance displacement Direction is moved.The control that spring 611L overcomes electromagnetic valve 55L to generate is pressed and is given along making servo piston The power of the direction effect that 610L recovers.Compression chamber 612L and the compression zone being arranged at servo piston 610L PR3 is corresponding, imports working oil from controlling pump 15 by electromagnetic valve 55L.

Feedback rod 62L is for the link rod by the Displacement Feedback of deflection driver 51L to guiding valve 600L Mechanism.Specifically, feedback rod 62L is, when working piston 510L moves, by its amount of movement Physically feed back to guiding valve 600L and make guiding valve 600L return to neutral position.

It addition, described above relates to pump control mechanism 50L, but pump control mechanism 50R is equally applicable.

Constituting according to above, the control pressure imported towards output control portion 61L, 61R is the biggest, then pump Actuator 50L, 50R make the output of hydraulic pump 14L, 14R more reduce.Additionally, towards output control The control pressure that portion processed 61L, 61R import is the least, then pump control mechanism 50L, 50R make hydraulic pump 14L, The output of 14R, more increases.

It addition, Fig. 8 represents the most unemployed state of hydraulic unit driver of excavator.Hereinafter, should State is referred to as " standby mode ".In stand-by mode, the working oil that hydraulic pump 14L, 14R discharges passes through Intermediate bypass pipeline 40L, 40R arrive negative control choke valve 41L, 41R, make negative control choke valve 41L, The negative pressure control that the upstream of 41R produces increases.

As a result, the finger that pump control mechanism 50L, 50R generates based on negative pressure control signal according to controller 30 Order, makes guiding valve 600L, 600R towards primary importance displacement.Guiding valve 600L, 600R are to deflection driver 51L, 51R are driven, and make the output of hydraulic pump 14L, 14R reduce.As a result, it is possible to suppression The working oil that hydraulic pump 14L, 14R discharge is by pressure loss during intermediate bypass pipeline 40L, 40R (pumping loss).

On the other hand, in the case of any one hydraulic unit driver of excavator is operated, hydraulic pump 14L, The working oil that 14R discharges flows into this hydraulic unit driver via the control valve corresponding with this hydraulic unit driver. Therefore, the amount arriving negative control choke valve 41L, 41R reduces or disappears, negative control choke valve 41L, The negative pressure control that the upstream of 41R produces reduces.

As a result, pump control mechanism 50L, 50R make the output of hydraulic pump 14L, 14R increase, and make abundance Working oil circulate to each hydraulic unit driver, enable the driving of each driver reliably to carry out.

Then, a part for the drive system 100 with reference to Fig. 9, the excavator of pie graph 7 carried Revolution hydraulic circuit 200 illustrate.It addition, Fig. 9 is the structure representing revolution hydraulic circuit 200 Become the synoptic diagram of example.

As it is shown in figure 9, revolution hydraulic circuit 200 mainly includes that revolution hydraulic motor 21, revolution subtract Pressure valve 71L, 71R and check valve 72L, 72R.

Revolution hydraulic motor 21 is via including mechanical brake 80 and the slew gear of decelerator 81 Upper rotation 3 is made to turn round.In the present embodiment, by being made up of the planetary gears in 2 stages Decelerator 81 amplify the output moment of torsion of revolution hydraulic motor 21.Additionally, by by multiple systems Moving plate and clip each brake disc multiple keep plates constitute mechanical brake 80, to revolution hydraulic pressure The rotation of the output shaft of motor 21 is braked.

Additionally, revolution with the 1st port 21L of hydraulic motor 21 via pipeline 70L and control valve 172L The 1st port P1 connect, revolution with the 2nd port 21R of hydraulic motor 21 via pipeline 70R with 2nd port P2 of control valve 172L connects.

By the pressure of the working oil in pipeline 70L, 70R (below, revolution air relief valve 71L, 71R are Referred to as " revolution hydraulic circuit is intrinsic pressure ") it is limited in the valve of below the revolution decompressed pressure of regulation.In this enforcement In example, revolution air relief valve 71L, 71R can also be to be set revolution decompression with fixing by spring etc. The fixed decompression valve of pressure.

Specifically, revolution air relief valve 71L reaches breakdown the revolution hydraulic circuit of pipeline 70L is intrinsic pressure Become partially open mode in the case of pressure, make the working oil in pipeline 70L start via pipeline 73 Flow out towards operating oil tank 22.Further, revolution air relief valve 71L is in the revolution hydraulic circuit of pipeline 70L Pressure becomes full-gear in the case of reaching to turn round decompressed pressure, makes the working oil in pipeline 70L towards work Make fuel tank 22 to flow out so that turning round that hydraulic circuit is intrinsic pressure will not exceedingly exceed revolution decompressed pressure.With Sample, revolution air relief valve 71R presses to the situation of opening pressure in the revolution hydraulic circuit of pipeline 70R Under become partially open mode, make the working oil in pipeline 70R start via pipeline 73 towards operating oil tank 22 flow out.Further, revolution air relief valve 71R turns round intrinsic pressure the reaching of revolution hydraulic circuit of pipeline 70R Become full-gear in the case of decompressed pressure, make the working oil in pipeline 70R towards operating oil tank 22 Flow out so that revolution hydraulic circuit is intrinsic pressure will not exceedingly exceed revolution decompressed pressure.

Hydraulic circuit is intrinsic pressure to be detected to turning round for pressure transducer S7L, S7R, and by detected Value as electricity revolution hydraulic circuit internal pressure signal export to controller 30.Specifically, work is made Oil flows into the 1st port 21L of revolution hydraulic motor 21 and makes revolution hydraulic motor 21 drive In the case of, the pressure of the working oil in pipeline 70L is detected, as returning by pressure transducer S7L Turn hydraulic circuit intrinsic pressure.Additionally, at the 2nd port 21R making working oil flow into revolution hydraulic motor 21 And in the case of making revolution hydraulic motor 21 drive, pressure transducer S7R is in pipeline 70R The pressure of working oil carries out detecting, intrinsic pressure as revolution hydraulic circuit.

Deflection angle sensor S8 is the sensor that the swash plate deflection angle to hydraulic pump 14L detects, will Detected value exports to controller 30.Additionally, angle of revolution velocity sensor S9 is to go back to top Turn 3 angle of revolution speed carry out the sensor that detects, detected value is exported to controller 30.

Figure 10 is to represent revolution hydraulic circuit working oil that is intrinsic pressure and that pass through in revolution air relief valve 71 The figure of the relation between flow (hereinafter referred to as " revolution decompression flow ").

As shown in Figure 10, in the case of revolution hydraulic circuit is intrinsic pressure less than opening pressure Pc, revolution Decompression flow is zero.Additionally, revolution hydraulic circuit intrinsic pressure for opening pressure Pc less than revolution In the case of decompressed pressure Pr, revolution decompression flow along with revolution the intrinsic pressure increase of hydraulic circuit and comparison delay Slowly increase.Additionally, in the case of revolution hydraulic circuit is intrinsic pressure for revolution more than decompressed pressure Pr, Revolution decompression flow increases more sharp along with the revolution intrinsic pressure increase of hydraulic circuit.

Check valve 72L, 72R are that the pressure making the working oil in pipeline 70L, 70R is not less than work The valve of the pressure (hereinafter referred to as " case pressure ") of the working oil of fuel tank 22.

Specifically, flow out and pipeline 70L towards operating oil tank 22 at the working oil forbidding pipeline 70L Revolution hydraulic circuit intrinsic pressure get lower than case pressure in the case of, check valve 72L becomes open mode, In making working oil feed line 70L of operating oil tank 22 (pipeline 73).Equally, pipeline 70R is being forbidden Working oil flow out towards operating oil tank 22 and the revolution hydraulic circuit of pipeline 70R is intrinsic pressure gets lower than case In the case of pressure, check valve 72R becomes open mode, makes the working oil of operating oil tank 22 (pipeline 73) In feed line 70R.

Main air relief valve 83 is in the main decompression specified by the pressure limit of the working oil in drive system 100 Valve below pressure.In the present embodiment, main air relief valve 83 is to be set with master regularly by spring etc. The fixed decompression valve of decompressed pressure.It addition, main decompressed pressure is set to higher than revolution decompressed pressure.

In the present embodiment, output based on pressure transducer S5, S6 is derived and is comprised revolution operation With or without the revolution operation content waited.It addition, pressure transducer S5, S6 be to revolution action bars 82 Guide's pressure corresponding to bar operational ton (hereinafter referred to as " pivoted lever operational ton ") the first pilot that carries out detecting pass Sensor.Additionally, derive hydraulic pump based on the output as the pressure transducer S3 discharging pressure sensor Pressure discharged by the pump of 14L.

Such as, detected towards right-hand rotation direction operation, pressure transducer S6 when revolution action bars 82 Guide when pressing liter, control valve 172L moves towards left.Now, control valve 172L passes through the 1st Port P1 makes hydraulic pump 14L connect with the 1st port 21L of revolution hydraulic motor 21, by 2 port P2 make the 2nd port 21R of revolution hydraulic motor 21 connect with operating oil tank 22.Additionally, Control valve 172L makes to be arrived the work of negative control choke valve 41L (with reference to Fig. 8) by intermediate bypass pipeline 40L Make flow-reduction or the disappearance of oil.As a result, negative pressure control reduces, the negative control of hydraulic pump 14L such as Fig. 3 Its pump discharge is made to increase as shown in line chart processed.

On the other hand, the amount of the working oil that the driving of revolution hydraulic motor 21 is consumed (below, claims Make " revolution consumed flow "), keep state that pump discharge than hydraulic pump 14L is low to increase lentamente. Its reason is, the upper rotation 3 of excavator has bigger moment of inertia.Now, hydraulic pump At least some of of the working oil that 14L discharges discharges towards operating oil tank 22 via revolution air relief valve 71L. Therefore, a part for the hydraulic energy that hydraulic pump 14L generates is not utilized gives up with being just wasted.

Therefore, controller 30 is in order to suppress this hydraulic energy given up lavishly as minimal Rotary torque is controlled simultaneously, and performs to turn round hydraulic pressure in the case of having carried out revolution operation The process of the authorized pressure of the intrinsic pressure opening pressure being adjusted to less than revolution air relief valve 71 in loop is (below, It is referred to as " the revolution intrinsic pressure adjustment of hydraulic circuit processes ").In the present embodiment, controller 30 is by making hydraulic pressure The discharge capacity increase and decrease of pump 14L, by turning round, hydraulic circuit is intrinsic pressure is adjusted to the regulation pressure less than opening pressure Power and rotary torque is controlled.

Herein, with reference to Figure 11 to performing to turn round the control system used when the intrinsic pressure adjustment of hydraulic circuit processes The configuration example of system illustrates.It addition, Figure 11 is the functional block diagram of the configuration example representing control system.

Specifically, the control system of Figure 11 includes that controller 30, attitude detecting portion E30, discharge capacity are examined Survey portion E31, revolution hydraulic circuit intrinsic pressure test section E32 and angle of revolution speed detecting portion E33.This Outward, controller 30 includes Model Predictive Control portion 34 and horsepower control portion 33.

Attitude detecting portion E30 is the functional imperative that the attitude to auxiliary equipment detects.In this enforcement In example, attitude detecting portion E30 is the Attitute detecting device detecting the attitude excavating auxiliary equipment M1.Attitute detecting device M1 based on the swing arm angle detected, dipper angle, scraper bowl angle and Fuselage angle of inclination and obtain position (position of bucket) Bp of the scraper bowl 6 as end auxiliary equipment, and This value is exported as electricity end auxiliary equipment position signalling to Model Predictive Control portion 34.

Discharge capacity test section E31 is the functional imperative that discharge capacity Vd to hydraulic pump 14L detects.? In the present embodiment, discharge capacity test section E31 be the swash plate deflection angle to hydraulic pump 14L detect inclined Rotary angle transmitter S8.Deflection angle sensor S8 obtains discharge capacity based on the swash plate deflection angle detected, And this value is exported as electricity displacement signal to Model Predictive Control portion 34.It addition, discharge capacity test section E31 can also carry out calculated pump rate according to discharge capacity command value Vt of last time, and using this value as electricity discharge capacity letter Number export to Model Predictive Control portion 34.

Revolution hydraulic circuit intrinsic pressure test section E32 is to the revolution intrinsic pressure function detected of hydraulic circuit Key element.In the present embodiment, revolution hydraulic circuit intrinsic pressure test section E32 is in revolution hydraulic circuit Pressure Pm carries out pressure transducer S7L, S7R of detecting, by the value that detected to Model Predictive Control portion 34 outputs.

The revolution intrinsic pressure Pm of hydraulic circuit is the pressure of the working oil in pipeline 70L, 70R.In this enforcement In example, controller 30 is, obtains pressure transducer S7R in the case of having carried out left revolution operation Output, as revolution the intrinsic pressure Pm of hydraulic circuit, carrying out right-hand rotation operation in the case of obtain pressure The output of force transducer S7L, the conduct revolution intrinsic pressure Pm of hydraulic circuit.

Angle of revolution speed detecting portion E33 is the functional imperative detecting angle of revolution speed.In this reality Executing in example, angle of revolution speed detecting portion E33 is that the angle of revolution speed omega to upper rotation 3 is examined The angle of revolution velocity sensor S9 surveyed.Angle of revolution velocity sensor S9 e.g. rotary encoder etc., The value detected is exported as electricity angle of revolution rate signal to Model Predictive Control portion 34.

Model Predictive Control portion 34 is to use including hydraulic pump 14L and revolution hydraulic motor 21 The model that is predicted in the movement of interior revolution hydraulic circuit, carry out in real time managing based on Optimal Control The functional imperative of the control (Model Predictive Control) of opinion.The Model Predictive Control of revolution hydraulic circuit is to use The control of the object model of revolution hydraulic circuit.Additionally, the object model of revolution hydraulic circuit is root The model of the output of revolution hydraulic circuit is derived according to the input for revolution hydraulic circuit.In this enforcement In example, Model Predictive Control portion 34 can according to angle of revolution speed omega, revolution the intrinsic pressure Pm of hydraulic circuit, Discharge capacity Vd of hydraulic pump 14L, the target revolution intrinsic pressure Pt of hydraulic circuit and the discharge capacity command value of last time Vt, that derives the future in finite time turns round the predictive value that hydraulic circuit is intrinsic pressure.

The target revolution intrinsic pressure Pt of hydraulic circuit is less than the force value of opening pressure Pc, is pre-stored within NVRAM etc..In the present embodiment, the target revolution intrinsic pressure Pt of hydraulic circuit builds with pivoted lever operational ton Stand and store accordingly.Specifically, the target revolution intrinsic pressure Pt of hydraulic circuit is set to, and pivoted lever is grasped Measure the biggest, become the biggest value.Controller 30 is, in the situation that revolution action bars 82 is operated Under, read target corresponding with the pivoted lever operational ton revolution intrinsic pressure Pt of hydraulic circuit from NVRAM.This Outward, controller 30 can also adjust target according to position of bucket Bp from attitude detecting portion E30 The revolution intrinsic pressure Pt of hydraulic circuit.

Specifically, the state of Model Predictive Control portion 34 use expression revolution hydraulic circuit is following Matrix equation derives the predictive value that revolution hydraulic circuit is intrinsic pressure.It addition, A, B are to represent revolution hydraulic pressure The coefficient matrix of the constructional feature in loop.

[numerical expression 2]

$\frac{d}{dt}\left[\begin{array}{c}\mathrm{\ω}\\ Pm\\ Vd\end{array}\right]=A\left[\begin{array}{c}\mathrm{\ω}\\ Pm\\ Vd\end{array}\right]+B\[Vt\]$

Specifically, angle of revolution based on current time, Model Predictive Control portion 34 speed omega, revolution liquid Push back discharge capacity command value Vt of the intrinsic pressure Pm in road, discharge capacity Vd and last time, derive angle of revolution speed omega, The revolution intrinsic pressure Pm of hydraulic circuit and the respective differential value of discharge capacity Vd.Then, returning current time Angle of revolution after tarnsition velocity ω is added with its differential value and derives as the stipulated time calculating object is fast The predictive value ω ' of degree.Rule are derived similarly for the revolution intrinsic pressure Pm of hydraulic circuit and discharge capacity Vd The revolution intrinsic pressure predictive value Pm ' of hydraulic circuit after fixing time and the prediction of the discharge capacity after the stipulated time Value Vd '.

Equally, Model Predictive Control portion 34 is derived by said method and uses the discharge capacity with last time constantly After stipulated time in the case of each of the multiple discharge capacity command value set on the basis of command value Vt Hydraulic circuit is intrinsic pressure and the predictive value of discharge capacity for angle of revolution speed, revolution.

On this basis, Model Predictive Control portion 34 select make target revolution the intrinsic pressure Pt of hydraulic circuit with Minimum is become as the difference turning round the intrinsic pressure predictive value of hydraulic circuit after the stipulated time calculating object Discharge capacity command value Vtc.Specifically, the multiple rows of discharge capacity command value Vt comprising last time are selected Measure in command value, as discharge capacity command value Vtc that should use specifically.

Then, Model Predictive Control portion 34 by selected discharge capacity command value Vtc to horsepower control portion 33 Output.

Horsepower control portion 33 uses discharge capacity command value Vtc that Model Predictive Control portion 34 selects to hydraulic pressure The discharge capacity of pump 14L is controlled.

Then, the intrinsic pressure Pm of revolution hydraulic circuit when revolution action bars 82 being operated with reference to Figure 12 Time passage illustrate.It addition, Figure 12 is to represent that revolution hydraulic circuit is intrinsic pressure and pivoted lever is grasped The figure of the time passage that work is measured.Additionally, the dotted line of Figure 12 represents the situation that have employed feedback control system Under time passage, the solid line of Figure 12 represents the time in the case of the control system that have employed Figure 11 Passage.It addition, the feedback control system as comparison other is following system: so that target revolution The deviation of the intrinsic pressure Pt of hydraulic circuit and the current revolution intrinsic pressure Pm of hydraulic circuit generates close to the mode of zero Discharge capacity command value Vt, and according to this discharge capacity command value Vt, discharge capacity Vd of hydraulic pump 14L is controlled.

In the case of have employed feedback control system, when carrying out turning round action bars 82 at moment t1 During full bar operation, the revolution intrinsic pressure Pm of hydraulic circuit starts to increase.Its reason is, hydraulic pump 14L The working oil discharged flows in revolution hydraulic circuit.It addition, full bar operation such as refers to turn round The neutral condition of action bars 82 is set to operational ton 0%, maximum mode of operation is set to operational ton 100% In the case of the state that operated with the operational ton of more than 80%.

Specifically, the revolution intrinsic pressure Pm of hydraulic circuit is exceeding target revolution hydraulic circuit intrinsic pressure Pt ground Minimizing is transferred at moment t2, afterwards, in being reduced below target revolution hydraulic circuit after adding It is returned to increase at moment t3 after pressure Pt.Afterwards, in the period of persistently full bar operation, liquid is turned round Push back the road intrinsic pressure Pm surrounding target revolution intrinsic pressure Pt of hydraulic circuit repeatedly increase and decrease and target turned round The intrinsic pressure Pt of hydraulic circuit elapses as in the pressure limit of the regulation of median.

So, controller 30 makes discharge capacity command value increase and decrease, and by feedback control to revolution hydraulic circuit Intrinsic pressure Pm is controlled such that its target become less than the opening pressure Pc of revolution air relief valve 71 is returned Turn the intrinsic pressure Pt of hydraulic circuit.Consume with revolution therefore, it is possible to expand by the revolution intrinsic pressure Pm of hydraulic circuit The size of the rotary torque of the product representation of flow can utilize scope.Specifically, it is possible to utilize ratio Employ there is the working oil of the pressure of more than opening pressure Pc in the case of the revolution that can obtain turn round The rotary torque that square is little.

In the case of have employed the control system of Figure 11, when carrying out turning round action bars 82 at moment t1 Full bar operation time, identical with the situation that have employed feedback control system, turn round the intrinsic pressure Pm of hydraulic circuit Start to increase.Its reason is, the working oil that hydraulic pump 14L discharges flows in revolution hydraulic circuit.

But, in the case of have employed the control system of Figure 11, and have employed feedback control system Situation is different, and it is intrinsic pressure that the revolution intrinsic pressure Pm of hydraulic circuit will not exceed target revolution hydraulic circuit significantly Pt and moment t10 reach target revolution the intrinsic pressure Pt of hydraulic circuit.Further, target revolution liquid is being reached The target revolution intrinsic pressure Pt of hydraulic circuit is maintained to elapse unchangeably after pushing back the intrinsic pressure Pt in road.Its reason is, The target revolution intrinsic pressure Pt of hydraulic circuit is exceeded at the revolution intrinsic pressure Pm of hydraulic circuit by Model Predictive Control Change discharge capacity command value before and prophylactically suppress to turn round the increase of the intrinsic pressure Pm of hydraulic circuit.Additionally, Its reason is, after the revolution intrinsic pressure Pm of hydraulic circuit reaches the target revolution intrinsic pressure Pt of hydraulic circuit, By Model Predictive Control at the revolution hydraulic circuit intrinsic pressure Pm breakaway revolution intrinsic pressure Pt of hydraulic circuit Change discharge capacity command value before and prophylactically suppress to turn round the disengaging of the intrinsic pressure Pm of hydraulic circuit.

So, controller 30 makes discharge capacity command value increase and decrease, and by Model Predictive Control to revolution hydraulic pressure The intrinsic pressure Pm in loop is controlled such that it becomes the mesh of the opening pressure Pc less than revolution air relief valve 71 The mark revolution intrinsic pressure Pt of hydraulic circuit.Therefore, it is possible to expand by the revolution intrinsic pressure Pm of hydraulic circuit and revolution The size of the rotary torque of the product representation of consumed flow can utilize scope.Specifically, it is possible to profit With than returning of can obtaining in the case of the working oil employing the pressure with more than opening pressure Pc The rotary torque that torque is little.

Additionally, the control system of Figure 11 is compared with feedback control system, it is possible to reduce hydraulic pump 14L's The operating lag impact on load change.Therefore, more stable by the intrinsic pressure Pm of hydraulic circuit will be turned round Maintain target revolution the intrinsic pressure Pt of hydraulic circuit, it is possible to more stably control rotary torque.

Above, embodiments of the invention have been carried out detailed narration, but the present invention has been not limited to specific Embodiment, can carry out various in the range of the purport of the present invention described in Patent request scope Deformation and change.

Such as, in the above-described embodiments, horsepower control portion 33 is according to each control cycle, according to model The minor variations Δ Vtc that PREDICTIVE CONTROL portion 34 selects calculates the discharge capacity command value that should use specifically Vtc.But, Model Predictive Control portion 34 can also refer to calculating discharge capacity according to minor variations Δ Vtc On the basis of making value Vtc, this discharge capacity command value Vtc is exported to horsepower control portion 33.

Additionally, in the above-described embodiments, controller 30 or Model Predictive Control portion 34 use pressure The output of sensor S7L, S7R is as the revolution intrinsic pressure Pm of hydraulic circuit but it also may use pressure to pass The pump of the i.e. hydraulic pump 14L of the output of sensor S3 discharges pressure as the revolution intrinsic pressure Pm of hydraulic circuit.

Additionally, in the above-described embodiments, Model Predictive Control portion 34 is incorporated in controller 30 Situation is illustrated, but Model Predictive Control portion 34 can also be with controller 30 split.

Claims (8)

1. an excavator, possesses:

Hydraulic unit driver；

The hydraulic pump of variable displacement, supplies working oil towards described hydraulic unit driver；

Model Predictive Control portion, quantity of state based on described hydraulic unit driver and the shape of described hydraulic pump State amount, is predicted the quantity of state of the described hydraulic pump after the stipulated time and derives for described hydraulic pressure The command value of pump；And

Control device, described hydraulic pump be controlled,

Described control device uses the instruction for described hydraulic pump that described Model Predictive Control portion derives Value, is controlled described hydraulic pump.

2. excavator as claimed in claim 1, wherein,

The quantity of state of described hydraulic unit driver is the flexible speed of the hydraulic cylinder as described hydraulic unit driver Degree, the pressure of working oil in described hydraulic cylinder or the operation rotated by described hydraulic cylinder will The rotational angle of element.

3. excavator as claimed in claim 1 or 2, wherein,

The quantity of state of described hydraulic pump comprises described hydraulic pressure pump delivery and discharges pressure.

4. an excavator, possesses:

Revolution hydraulic motor；

The hydraulic pump of variable displacement, supplies working oil towards described revolution hydraulic motor；

Revolution air relief valve, is configured at and described revolution hydraulic motor and described hydraulic pump is attached On pipeline；And

Controller, is controlled the rotary torque of described revolution hydraulic motor,

Described controller make described hydraulic pressure pump delivery increase and decrease and by turning round, hydraulic circuit is intrinsic pressure is adjusted to low In the authorized pressure of the opening pressure of described revolution air relief valve, thus to described revolution hydraulic motor Rotary torque is controlled.

5. excavator as claimed in claim 4, wherein,

Possess the revolution intrinsic pressure intrinsic pressure test section of revolution hydraulic circuit detected of hydraulic circuit,

The revolution hydraulic circuit that described controller detects according to the described intrinsic pressure test section of revolution hydraulic circuit Intrinsic pressure, make described hydraulic pressure pump delivery increase and decrease.

6. the excavator as described in claim 4 or 5, wherein,

The decompressed pressure of described revolution air relief valve is fixing.

7. the excavator as according to any one of claim 4 to 6, wherein,

Described controller is according in the revolution hydraulic circuit intrinsic pressure Yu current based on target revolution hydraulic circuit The deviation of pressure and the discharge capacity command value that generates, carry out feedback control to described hydraulic pressure pump delivery.

8. the excavator as according to any one of claim 4 to 7, wherein,

Possessing Model Predictive Control portion, this Model Predictive Control portion is to employing multiple discharge capacity command value In the case of stipulated time after revolution hydraulic circuit intrinsic pressure be predicted,

Described Model Predictive Control portion selects current revolution hydraulic pressure to return from the plurality of discharge capacity command value Road intrinsic pressure with the stipulated time after the intrinsic pressure difference of revolution hydraulic circuit become minimum discharge capacity command value,

Described controller uses the discharge capacity command value that described Model Predictive Control portion selects, pre-by model Described hydraulic pressure pump delivery is controlled by observing and controlling system.