AU592807B2 - The determining of the amount of material delivered each operational cycle of a shovel loader - Google Patents

Description

i AUJ-AI 9 6 91 /86 WORLD INTELLECTUAL PROPMY O ilON8 0 PT International lu |j 8 O j INTERNATIONAL APPLICATION PUBLISHED UNDER THEPATENT COOPERATION TREATY (PCT) (51) Inteinational Patent Classification 4 (11) International Publication Number: WO 86/ 07399 E02F 9/26, G01G 19/12, 19/413 Al (43) International Publication Date: 18 December 1986 (18.12.86) (21) International Application Number: PCT/AU86/00167 (22) International Filing Date: (31) Priority Application Number: (32) Priority Date: (33) Priority Country: 9 June 1986 (09.06.86) (81) Designated States: AT (European patent), AU, BE (European patent), CH (European patent), DE (European patent), FR (European patent), GB, GB (European patent), IT (European patent), JP, LU (Eurnpean patent), NL (European patent), SE (Europeapatent), SU, US. PH 0953 7 June 1985 (07.06.85) Published With international search report.

(71) Applicant (for all designated States except US): ACET LIMITED [AU/AU]; 22-24 Hasler Road, Osborne Park, W.A. 6017 (AU).

(72) Inventors; and Inventors/Applicants (for US only) BLAIR, James, Ross [AU/AU]; 11 Langham Road, Nedlands, W.A.

6009 RILEY, Timothy, William [AU/AU]; 4 Riley Road, Kardinya, W.A. 6163 (AU).

(74) Agent: EDWD. WATERS SONS; 50 Queen Street, Melbourne, VIC 3000 (AU).

This document contains the amendments made under Scction 49 and is correct for printing.

(54) Title: THE DETERMINING OF THE AMOUNT OF MIATERIAL D CLE OF A SHOVEL LOADER .ED EACH OPERATIONAL CY- (57) Abstract A method and apparatus for measuring the quantity of material delivered per cycle by a shovel loader having a bucket (22) that is moved between loaded and unloading positions. During the movement of the bucket in either direction between said positions, determinations are made of the location of the bucket with respect to two spaced points and (17) on the structure (15) supporting the bucket. At the same time determinations are made as to the strain at a particular location in the support structure that strain being related to total weight of the bucket and its contents. The bucket position determinations and the strain determinations are each provided as inputs to a processor programmed to calculate therefrom the weight of the bucket and contents, when loaded and unloaded, to thereby provide the weight of material delivered.

THE DETERMINING OF THE AMOUNT OF MATERIAL DELIVERED EACH OPERATIONAL CYCLE OF A SHOVEL LOADER This invention relates to the determining of the amount of material delivered each operational cycle of a shovel loader. In particular the invention relates to effecting such determination in regard to a shovel loader comprising a base, a platform supported on the base for rotation relative thereto about a vertical axis, a boom connected to the platform at the lower end and at an upper portion to a stay structure mounted on the platform so the boom extends upwardly and outwardly from the platform, and a bucket supported suspended from the boom and displaceable therefrom in a vertical and horizontal direction.

eeoc :15 It is desirable for a number of reasons to be able to determine the quantity of material delivered by a shovel loader both from the point of view of material delivered per operational cycle of the loader and total quantities over small and large numbers of cycles.

Apart from ascertaining the total quantity of material moved in a day or a shift, when loading vehicles by a shovel, it is important to ensure the truck is not under or over loaded. Underloading is wasteful in regard to e 9 vehicle usage, and overloading is detrimental to vehicle 25 wear and overall life.

It is therefore the object of the present invention to provide a method and apparatus that is effective in measuring the quantity of material delivered each operating cycle of a shovel loader, having regard to the environment :30 in which the shovel loader operates and various factors influencing the accuracy of such measurements.

With this object in view there is provided a method of measuring the quantity of material delivered per cycle -1aby a shovel loader having a bucket to hold the material to be delivered, the bucket being movable between loaded and unloading positions, said bucket being supported from a structure during movement between said positions, said method comprising determining the position of the bucket in respect to a selected fixed location on said structure in the form of a processable position signal at a plurality of intervals during the movement of the bucket uetween said loaded and unloading positions, determining the load at a selected fixed location within said structure where the load is related to the mass and position of the bucke) contents in the form of a processable lead signal at each said interval, processing said position and load signals for a plurality of interval determinations to provide a 15 number of mass determinations of the bucket and bucket contents from the interval determinations made during said movement, and averaging said mass determinations to provide a final mass determination of the bucket and bucket .e contents.

66 *0 o 0 0 o oo Go! -2- More specifically there is provided a method of measuring the quantity of material delivered per cycle by a shovel loader comprising a base, a platform supported on the base for rotation relative thereto about a vertical axis, a boom mounted at the lower end on the platform and connected at an upper portion to a stay structure mounted on the platform so the boom extends upwardly and outwardly from the platform, and a bucket supported suspended from the boom and displacable therefrom in a vertical and horizontal direction, said method comprising determining in the form of an electrical signal the position of the bucket in respect to a selected fixed location in the boom or stay at a plurality of intervals during the rotation of the platform to move the bucket between loaded and unload- 15 ing positions, determining in the form of an electrical signal the load at a selected fixed location in the boom or said stay structure where the load is related to the mass and position of the bucket and bucket contents, processing said position and load electrical signals for plurality of interval determinations in an electronic processor to provide a number of mass determinations of the bucket and bucket contents from the interval determinations made during said movement, and averaging said mass determinations to provide a final mass determination of the bucket and bucket contents.

5y determining the difference between the weight of the loaded bucket as it moves to the unloading position and weight of the empty bucket as it returns from the unloading position, the weight of the contents of the bucket actually deposited is ascertained. The processor determines an average of the weights calculated during the respective movements and provides a difference in these 2'

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15 o0 0 oo 3 1. averages as the weight of the contents deposited by the bucket.

Conveniently the determinations are made at predetermined time intervals during the movement of the boom in each direction. The time intervals between the determinations are preferably equal.

These weight determinations may be initiated and terminated in response to suitable parameters, such as the position of the boom relative to the base of the loader, or the angular velocity or acceleration of the boom relative to the loader base.

Conveniently the initiation of the making of the determination of the weight of the loaded bucket may be in response to the bucket occupying a selected position relative to the boom that is indicative that the loading of the bucket has been completed.

The termination of weight determinations may similarly be in response to the bucket occupying a further selected position relative to the boom indicating the bucket is about to discharge its load. The initiation and termination of the determination of the weight of the 0000 00 oo S 0 0 00* 0000

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o S S 0 ooo -3 unloaded bucket are simrilarly in responsae to selected positions in the moveiment of the bucket and4/or boan.

It has been foundl that the aonaracy of the determination of the weight of the load discharged is increased if the averaging oi the determinations of weight of the loaded and unloaied bucket, does not include the determinations at or ne-ar the respective ends of the respective nVements of the boomi, particularly at the ccmencement of the rovements. This is because at these periods substantial kinetic load may be experienced anxi these 'Loads ray fluctuate significantly within those periods. zdnlit is preferable to exclude frcm the averaging step a nurber of the weights calculated at one or both ends of the respective navements of the boom.

The position of the bucet relative to the bomi ray be determined by the masurement of the distance of a reference point on the bucket frcm two fixed points on the boczu, one o~f which may be the pivot axis of the conrection batween the boci azyi the arm carrying the *bucket.

cmweniently the bucket is oupledi to a rigid memnber pivotally connected to both the buckemt and the bczi with the effective length of the memnber between these pivot connections adjtble. "-e *bucket is also suspended from a sheath at the upper e-4 of the bocra, tr *r -e yS.atdio a cable or cables. The bucket is raised or lowere yceatxio *winch dru ab.a which the cable or (cables are wound.

The position, of the bucket relative to the boom may be ascertained using suitable sensors which provide respective signals to the prcessor indicating the linear displacement of a reference point on the bucket from tha connection of the member to the bocin and the length of cable betwecn the sheath andl the bucket, The- processor is Programmed to detereine from these aignals the co-ointes of the centre of gravity of the bucket with respect to ars approupriate fixed reference on the loader platform or boom.I strain gauges or other suitable load sensing m, aiv are provided to generate a signal having a )arwn relation to the total weight supported by the toan. The strain gauges or sensing reams ray be arranged determine the strain in a Celected. section Of the bocz or the stay structure interconnected between the bomi and the loader platform. The electronic Processor is programmed to calcul ate fran N this signal, and the sign4.ls received indicating the position Of the WO 86/07399 PCT/AU86/00167 -4bucket, the total weight supported by the boom, frm which the total weight of the bucket and its contents is derived.

The processor is further programmed to make a series of such calculations when the bucket is loaded and after deposit of the load in any one cycle, and then determines the difference between the average loaded and unloaded weight support by the boom to achieve the weight of material delivered by the loader each cycle.

In many shovel loaders kinetic forces arising frcm the move t of suh ccaponent as the bucket, bucket arm, boom, will give rise to stresses in the structural member in which the strain is being measured. zccordingly in order to correct for these kinetic forces in the bucket load determinations, the linear and angular velocity and acceleration of major components, such as the uacket and the platform supporting the boom, are sensed and fed to the processor. The processor is programmed with static information regarding the mass of the relevant components, and the physical relation thereof to the structural mezber, so that, with sensed information regarding the velocity and/or acceleration experienced by the canponeff.s, the processor can effect the necessary ccmpensation for kinetic forces in determining the buqket load.

An example of such forces encountered durirg the movement of the bucket from the loading to the dumping position, where that movement is a swinging movement about a vertical axis, is the centrifugal forces acting on the bucket, boom and other component having rotary motion. It will be appreciated that the kinetic forces that induced strains in the structural member, wherein strains are measured for load determinations, will be dependent on the overall physical construction of the shovel loader. However, the relevant forces can readily be identified by suitable analysis of khe structure, and appropriate programming incorporated in the processor to compensate for these forces in the bucket load determinations.

The position of the bucket relative to the boom may be determined by suitable electronic'- sensors such as optical enccders. As previously referred to the bucket may be coupled to a rigid member pivotally connected to both the bucket and the boom with the effective length of the member betwext these pivot connections adjustable, and the bucket also suspended, frcm a sheath at the upper end of the boom, by a cable or cables coupled to a winch drum. Accordingly, the length WO 86/071399 PCTiAU86/00167 of cable between the bucket and the sheath is a controlling factor in the position of the bucket relative to the boom. The winch drum is Oriven by an electric motor through suitable gear train, and an optical encc-er is coupled to the gear train so the signal output therefra is related to the length of cable between the sheath and the bucket. An electric motor is provided coupled via a suitable speed re uction, to a drive mechanism that extends the member relative to t-he bxx=, ani an encoder is coupled to the drive so the rotation thereof is proportional to the degree of extension of the member. The output from the two encoders may be fed to the electronic processor through, if necessary, appropriate amplifiers, and the ccmtar program can determine from these signals the actual. disposition of the centre of gravity of the bucket relative to a selected reference point on the boom, such as the lower point of connection of the boom to the platform or shove] loader, or the upper point of connection of the boom to the stay structure.

In this regard, it is to be understod. that the boom primarily retains a fixed position relative to the platform during the normal operation of the shovel loader. However, if the constructions of the shovel loader is such that the boom position may be -aried during operation, then a further encoder would be provided to produce a signal to indicate the angular disposition of the boom to the platform, and that signal would be a further input to the processor, which would be programmed to also take into account this i-::lination when determining the position of the bucket. The output of such an encoder may also be processed to provided measurement of the velocity ar4/or acceleration of the various structural component for the purpose of determining kinetic force.

Normally, the upper portion of the boom is connected to the stay structure by a rigid or flexible member or members, which are arranged so as to be under tension under all operating conditions. In the alternative construction wherein the inclination of the boom may be adjustable, these temnion umbers may also be in the form of cables, wh1ch can be extended or retracted as required. The tension member, whether of a fixed or variable length, is connected to or passed around a rigid strut or stay rigidly secured to the platform. The strain in the tension member or the strut or stay thus has a cal'xlable relationship with the load supported by the boom. It is theocefore possible to locate a suitable strain or stress serving device on the d WO 86/07399 PCT/AU86/00167 WO 86/07399 -6tension member or another appropriate member or members in the stay structure, which will produce a. signal having a calculable relationship to the weight supported by the boom. It is preferable for the -ensor to be attached to a rigid member rather than a flexible member, as this reduced the complexity of the relationship between the stress or strain in that member and the load supported by the boom.

The intervals at which the readings are taken to record the position of the bucket, and the strain in the relevant member of the stay structure, are identical. The initiation of recording and processing of bucket position and r-ain readings is deterined by sensing the commencemant of the movement of the boom beyond a predetermined point in its rotary movement relative to -he platform, or the movement of the bucket beyond a preselected location relative to the boom, such location being selected as one which the bucket occupies during transit, and does not occupy during normal collection of the material into the bucket.

S3nlarly, at the deposit end of the Movement of the bucket, a sensor is provided to determine the commencement of depositing of the material. Such a sensor may be related to the release of the door of the bucket to deposit the material.

The initiation and termination of the recording of the signal indicating the bucket position and strain in the stay structure may be in response to 'he platform supporting the boom passing through selected angular relationships to the shovel base. The rotation of the platform relative to the base is achieved by an electric motor driving through a suitable gear box. A suitable encoder may be coupled to this drive train, via a further gear reduction if necessary, so the encode effects one revolution for a complete revolution of the platform.

Accordingly, after appropriate calibration the relative angular position of the platform, and benca of the boom mounted thereon, can be sensed by the processor on the basis of the output from the encoder.

This arrangement enables the processor to initiate and terminate the recording of the signals indicating the bucket position and stay structure strain within a selected range of angular relationships between the boom and the shovel base. The particlar range being selected to within the range of Movement between the loading and unloading position of the bucket. The direction of the changes in the encoder reading, ie. increasing or decraasing, will indicate to the processor the direction of movement of the boom.

There is also provided by the present invention a shovel loader having a bucket supported from a structure being movable to locate the bucket in respective loaded and unloading positions, apparatus for measuring the quantity of material delivered by the bucket per shovel cycle, said apparatus comprising means to determine the position of the bucket with respect to a selected location in the structure at a plurality of intervals during said movement of the bucket, means to provide a processable position signal indicative of the determined position of the bucket, means to determine the load at a selected location within the e.

structure where the load is related to the mass of the bucket and bucket contents at said intervals during said g o movement of the bucket, means to produce a processable load S signal indicative of the determined load at said location, and processing means to receive said position and load signals for a plurality of interval terminations and 20 calculate therefrom a number of mass determinations of the bucket and bucket contents from the interval determinations made during said movement, and to average said mass determinations to provide a final mass determination of the bucket and bucket contents.

The invention will be more readily understood from the following description of application thereof to a known dipper type of shovel loader and with reference to the accompanying drawings.

In the drawings; Figure 1 is a simplified drawing showing the general construction layout of the dipper shovel loader.

-7a- Figure 2 is a diagrammatic representation of the various sensors and processors used in effecting the dipper load determinations.

Figures 3 and 4 together are a logic diagram from the program of the processor.

Figure 5 is a diagrammatic representation of an optical encoder for signaling to the processor the position of various components of the shovel loader.

Referring to Figure 1 the shovel loader depicted therein of the well known construction commonly referred to as a dipper shovel loader. This shovel loader comprises a mobile base 10 supported on drive tracks 11, and having supported thereon through the turntable 12, a machinery deck 13. The turntable 12 permits full 360 degrees 15 rotation of the machinery deck relative to the base.

9 0 I The boom 15 is pivotally connected at 16 to the .o6 machinery deck, and carries at the upper end of a cable sheath 17. The boom is held 0*

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*d *0 t WO 86/07399 PCT/AU86/001 67 in a fixed upwardly and outwardly extending relation to the deck by the tension cables 18, which are anchored to the back stay 19 of the stay structure 20, rigidly nmOted on the machinery deck 13.

The bucket or dipper 22 is suspended by the cable 23 from the sh eath 17, the cable being anchored to the winch drum 24 mounted on the machinery deck 13. The dipper lias an arm 25 rigidly attached thereto, with the dipper arm 25 slidably supported in the saddle block 26, which is pivotally mounted on the ]x 15 at 27. The dipper arm has a rack tooth formation thereon (not shown) which engages a drive pinion, (not shown) mounted in the saddle block 26. The drive pinion is driven by n electric motor and transmission unit 28 to effect extension or retraction of the dipper arm 25 relative to the saddle block 26.

An engine driven electric generator is mounted on the machinery deck to provide power to respective electric motors which drive the winch drum 24, saddle block transmission unit 28, and machinery deck tuntable 12. As previously explained, the position of the dipper 22 relative to a selected fixed reference point on the boom may be determined by k!owing the extent of projection of the dipper arm 25 with respect to the saddle block 26 and the effective length of the cable 23 between the sheath 17 ard the dipper 22. The above described bas c construction of the shovel loader is widely known and used and o er details of the construction are not provided as they are well known in the art.

n the operation of the shovel, loader a baz-ic series of movements if the dipper are associated with each delivery of material to the truck or the like. Although the operator may perform other operations with the dipper between deliveries of the materiaA to the truck, it is possible to reccgnise when the loader is delivering material to the truck and when it is merely being operated to clean up loose material in the loading viciniLy or carryig out such other operations that are not directly involved in a loading sequence.

17The sequence of loading operations are: 1. Loading the dipper with material whgin te ,N I lcwered position.

2. Raising the dipper to an elevaa'd pose 3. Swingirn the dipper whilst in an IIt the vertical axis from a digging positiLn tc .on.

4. Opening the dipper door when the dIj>_ n: "e unlo;IdTng -9position.

Returning the dipper from the unloading position to the digging position.

6. Closing the dipper door when the dipper is moving towards the digging position.

As, in the preferred operation, the load weighing procedure is carried out while the dipper is swinging in the raised position, it is convenient to arrange that processor only places in store dipper load calculations made whilst the dipper is in a raised position. This raised position can be readily determined by the angular relationship between the dipper arm 25 and the boom The processor can determine this angle from a calculation based on the length of cable played out from the winch drum 24 and the position of the dipper arm 25 relative to the e saddle block 26 determined by the position of the rack on the dipper arm relative to the driving pinion. Load calculations made whilst the dipper was not in the raised position would not be considered in calculating the loaded or unloaded weight of the dipper.

Determination that the dipper is swinging can be obtained by detecting rotation of the motor driving the turntable 12 or of' a component in the turntable drive transmission. This is conveniently achieved by an optical 25 encoder unit incorporating a member coupled to the turntable drive to rotate in a fixed speed relation to the machinery deck rotation. The extent of angular movement 4 of the machinery deck, and the angular velocity and acceleration thereof can be calculated by the processor from the signals received from the encoder. The general construction and operation of the optical encoder is

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4 1 rE i -9adescribed hereinafter.

The processor is thus able to determine, from the turntable encoder, when the boom 15 and dipper 24 are swinging between the digging and dumping positions in either direction, and make the dipper load calculations during those periods. As previously referred to these calculations are made at fixed time intervals, during the swinging movement, and calculations made during the initial and terminal portion of the swinging movement are discarded in the load averaging to avoid the effects of kinetic forces in the shovel loader structure. The load calculation to be discarded can be counted from the initial and final signal received from the turntable encoder in each swinging movement.

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-1 ~il o WO 86/07399 PCT/AU86/00167 "U A similar optical encoder unit is incorporated in the drive of the winch drtm 24 so that the length of cable played out from the winch drum can be calculated fror the rotation of the drum. The processor can calculate from this the distance between the centre of mass of the dipper and the axis 35 of the sheath 16, this being one co-ordinate in determining the position of the dipper. Again the encoder unit will provide velocity and acceleration data to be used in determining kinetic forces arising fron the dipper movement.

A further optical encoder unit is incorporated in the drive of the pinion that exters or retracts the dipper arm 25 relative to the saddle 26. From this irut the processor can calculate the distance between the centre of mass of the dipper and the axis 27 of the pivot connection between the saddle 26 and the boon Accordingly, fran the encoder units on the winch drunm drive and the dipper arm drive the processor ha?' ,'iinates of the centre of mass of the dipper in respect of the U fixed points on the boom Knowing the co-ordinates of th centre of mass of the dipper in respect of the fixed points on the boon it can be determined mathematically the strain that the weight of the dipper and its contents induce in any part of the boom or its support structure.

Conversely knowing the strain in a eledted part of the support structure and the disposition of the centre of mass of the dipper the weight of the dipper and its contents can be calculate, In such a calculation account will have to be taken of the other strain inducing loads act on that part of the structure including kinetic loads.

Accordingly, by suitably programmir, the processor and providing signals thereto regarding the position of the dipper, and the strain in a selected part of the structure the processor can deteza;nine the weight of the dipper plus contents if any. It will be appreciated that the actual program will part with the construction of the shovel loader and the location of strain measurement. However, the development of the particular mathematic formula and a program based thereon is within the skill of capetent engineers.

In a shovel loader of the configuration shown in Figure 1 it has been found that a desirable location of strain gauges is on the vertical member of the back stay 19. The strain in the back stay is of a less cnr-isx nature than that in many other areas of the structure, woD 86/07399 PCT/AU86/00167 and has a relatively convenient relationship to the weight of the dipper and its contents.

Figure 2 of the drawings shows one furctional arrangement of the various enooders and processors to perform the present invention, as applied to the dipper type shovel loader described with reference to Figure 1.

The winch drum, dipper arm, and turntable optical encoders previously referred to are represented at 81, 82 and 83, and each provide serially information to the secondary processor 85 which prepares the encoder information for processing by the main processor Other basic information regarding the operating condition of the loader is provided fzcm the shovel control 86 via the interface unit 87 and the converter 88 to the main processor 95. This other basic information relates to whether the shovel is the operating condition, whether the shovel is performing loading operation, or is in a mobile state, moving between working site etc. This information is relevant to the main processor deciding if the shovel is delivering material, and therefore the processor should make a weight calculation.

oC\ The strain gauge units 91 and 92 are mounted e-ef the two upright mambers forming the back stay 19 in Figure 1 and produce a signal proportional to the strain in said back stay. This signal iUs also passed through the converter 88 to the main processor The main processor is progranmed, as previously discussed to calculate from the inputs the weight of the bucket and contents for each position and load determination, and to provide an average weig", t for each loaded and unloaded cycle of the shovel.

The resultant weight of material delivered each cycle as calculated by the main processor 95 is passed to the solid state storage of the secondary processor 85. The secondary processor can on a radio lirk transmitted coaid of a remtce base computer transfer infornition frm the secondary processor memory to the base computer via the radio modem 98 and radio unit 99.

The operator display 96 is suitably located for viewing by the shove, operator, and via the graphic processor 94 receives regularly updated information regazding the weight of material delivered each cycle ce the shovel and the total weight dealivered to each truck.

suitable ccmmrially Aailable processors for use in the WO PCT/AU86100 107 WO86/07399 -12above described arrangement are: Main Processor Motorola MC68 000 Secondaary Processor Motorola MC6802 Graphxic Processor Motorola MC6802 Referring no to the simp~lified logic diagram of Figure 3 and 4the basic decision and operations of the processor will be described.

fors thqene pardiclrsinatd bpeaiour of th iperda;olosa 4.t demiterainehif the diper dio is opein.

1.da gahef the dorisoenriousr thodratd the pprain transituafter dhekinema loaou the caclte dipper load ism h stor iformubequntvrgn 3.b Ifcuat the dipper o is ce the dtripe gaye inoonetoo the stats. rknmti eaiu o h ipr 4dg.ng deteriale toiil the dipper.do s pn 2. If th atoo is inctinsttn the dippern tra diit aftr dmiper odr ptions.lae dperladi 3.re "waitibse"unt ave psitintng. nt n h tIf ntdiprdoiscoethdierm bein in posteo toreeie 2-the protesso eemnsi ihofteetresae h 4 dipper is.asdpreiousl disusedia theilre oed in ccrdncrwt tha deerintin igta si rnibtentedpe Theadeio ns daperatmins pofitheocesrldi 3 eaho"weesait g of th dipin~ be descrined witurefere to igue rLes determie nwiho thes three hedns"ig siaiges ahe thadtrinaton Digging.

1. determine the state of the dipper at the time of the previous cycle.

a. if the dipper was also digging in the previous cycle the current dipper load calculation is not required to be stored. Accordingly the stored average dipper load will be WO 86/07399 PCT/AU86/00167 {3 reset to zero, and the previous state memory set to "digging'.

b. if the state of the dipper was not "digging" on the previous cycle then the dipper has just completed a return swing after dumpfing material in the back. The processor nw ave-ages the dipper load calculations stored during the retuLn swing of the dipper to determine the average empty dipper weight. The processor will have stored therein the average full dipper weight as determined during the preceding swinging movement of the dipper from the digging to the dumping position, w-4 now calculates the weight of material dumped by subtracting the empty dipper weight from the f rll dipper weight. The determined dumped weight of material is transmitted to a secondary processor and stored for subsequent retrieval such as by transmission by radio link to a remote storage or further processing facility.

The determined duped weight is also transmitted to visual display for shovel operator viewing. Thereafter stored average dipper weight is reset to zero ard the previous state memory set to "diggirr".

Swinging.

1. Determine the state of the cipper at the tine of the previous cycle.

a. if the dipper was swinging during the previous cycle, a check is made that the direction of swirg ia the same and if so the dipper load is calculated and stored, and the current avez -ge dipper load for that particular swing is calculated for operator display. This sequence is repeated each cycle so 1c_4k as the dipper is swinging in the sae direction and until the dipper door is opened indicating a change in direction of swing as previously discussed. The average dipper load on the operator display is only updated each 2 secs.

b. if the dipper was "waiting" during the previous cycle this indicates that the loaded dipper is in position to dump a load into a truck, but the truck is not in position.

This means that the previous truck has been filled and departed and a further truck is to move into position. The

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WO 86/07399 PCT/AU86/00167 .1.4 processor is thus advised a change of truck is in progress and enters this to the memory and totals the load delivered to the previous truck and transmitted same to the secondary processor and stored.

Waiting.

While in the waiting state there are no changes taking place so that the current calculated dipper load is stored and the previous state set at waiting. This cycle repeats until a change of state is signaled.

It will be understood that the dipper enters the "waiting" state at the end of a swing in one direction, with the dipper loaded, and leaves the waiting state at the c..nc .ent of a swing in the opposite dire&.tion. While in the waiting state the "dipper door will be operated to open and deposit the load in the truck. Thus the operator initiated opening of the dipper door is used to signal to the processor a change in direction of swing. Similarly the closing of the dipper door occurs at the end of the return swing of the dipper to the digging position and so -alan indicatesthe pending next change of direction of swing of the dipper.

Reference has previously been made to optical encoders coupled to the electric motors or transmissions which drive the winci, j drum, the dipper arm pinion, and the turntable, as sensors to determine the position and movement of the respective crponents. Encoders for these purposes may be of any known form having the required capacity and accuracy. One ccmparatively simple but effective form of encoder is shown diagrammatically in Figure The encoder cmprising ard input shaft 102, j ournaled in bearings 103 and 104, and carrying the first coded disc 105 and pinion 106. The end portion 107 of the shaft 102 is in use coupled suitably to the motor or transmission driving the component, the position of which is being monitored, such as the winch dunm or turntable.

The pinion 106 drives the gear 108 mounted on the lay shaft 109, on which is also mounted the gear i0. The shaft 109 is supported in bearirxs 111 at each end, and the sothaft 109 and gears 108 and rotate in unison. The gear 110 drives gear 112, mounted on sha f 113 carrying the second coded disc 114. The shaft 113 is supported in bearings 115 and the shaft 113, gear 112, and secord coded disc 114 rotate in unison.

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WO 86/07399 PCT/AU86/00167 *WO 86/07399 4 The two gears trains 106 108 and 110 112 provide a double reduction in speed between the first and second ceded discs 105 and 114. This speed reduction is selected so that the secnd coded disc 1 114 will advance one cede interval for each revolution of the first coded disc 105. The speed reduction between the first coded disc and 4 the member driving it is selected, having regard to the relative Smovement of the cmponent being monitored by the encoder. The second coded disc 114 is required to eff-ct no more than one comaplete revolution for the full extent of movement of the monitored cmponent.

J 10 Each coded disc 105, 114 is provided with an optical -cde pattern around its perimetal area, of any suitable form, such as the 'Grey Pattern'. A light source ard receiver units 120 and 121 are provided for the respective discs 105, 114 to generate with the perimetal pattern a digital signal indicative of the rotational position of each disc. It will be appreciated that the signal from the first disc 105 divides each interval of the second disc 114 by the number of intervals on the first disc. Accordingly, the output from the two discs provide an accurate tracking of the position of the component being monitored.

In addc.ition, the signal from the first coded disc can be processed to provide velocity and acceleration data in respect of the monitored c-mponent.

It will be understood that the mathematical formula upon which the programme of the processors is based will be dependent on a number of factors including the general geometry of the shovel loader structure supporting the bucket, the particular location of the strain gauges or the like on the struccrce, and the fixed points selected on the structure from which the bucket co-ordinates are measured.

However, the formula are, based on fundamental engineering principles well known in the art and by those skilled in the art.

Claims (11)

1. A method of measuring the quantity of material delivered per cycle by a shovel loader having a bucket to hol. the material to be delivered, the bucket being movable between loaded and unloading positions, said bucket being supported from a structure during ovement between said positions, said method comprising determining the position of the bucket in respect to a selected fixed location on said structure in the form of a processable position signal at a plurality of intervals during the movement of the bucket between said loaded and unloading positions, determining the load at a selected fixed location within said structure where the load is related to the mass and position of the bucketXcontents the form of a processable load signal at each said interval, processing said position and load signals for a plurality of interval determinations to provide a number of mass determinations of the bucket and bucket contents from the interval determinations made during said movement, and averaging said mass determinations to provide a final mass determination of the bucket and bucket contents, the mass of the empty bucket being subtracted to provide the mass of material delivered.

2. A method as claimed in claim 1 wherein first position determinations and first load determinations are made as the bucket moves from 'he loaded to the unloading positions, and second position determinations and second load determinations are male as the bucket returns from the unloading position toward the loaded position, processing said position and load signals from said first position and load determinations to provide a final mass determination of the bucket and bucket contents when the bucket is loaded, processing said position and load signals from said second position and load determinations to provide a final mass V^ L L- r. -17- determination of the bucket and bucket contentp after the bucket has been unloaded, and processing th final mass determinations of the loaded and unloaded bucket to provide a final mass determination of material delivered from the bucket.

3. A method as claimed in claim 1 or 2 wherein the position of the bucket is determined by determining the distance from a selected point in the bucket to two 4 spaced fixed points of the structure, said two spaced fixed points having a fixed relation to the location at which the load in the structure is determiaed.

4. A method as claimed in claim 1, 2, or 3 wherein the structure is mounted for movement about a vertical axis to effect movement of the bucket between said loaded and unloading positions. A method as claimed in Claim 4 wherein said position determinations and said load determinations are made at fixed time intervals during at least part of the S**movement of the structure about said vertical axis to and from the bucket unloading position.

6. A method as claimed in any one of claims 1 to wherein position and load determinations are processed to provide mass determinations only when the bucket is at or above a predetermined height with respect to the structure.

7. A method as claimed in any one of claims 1 to 6 wherein the velocity and acceleration of the structure I -18- and the bucket are determined during the movement of the bucket between said loaded and unloading positions in the form of processable kinetic signals, and said kinetic signals are processed to determine that portion of the load at said selected location resulting from said velocity and acceleration and effecting correction to load determination accordingly.

8. A method as claimed in any one of the preceding claims i: wherein the load at said selected location in the structure is determined by a load cell means that produces an electrical S signal proportional to the strain in the structure at said location. i A method of measuring the quantity of material delivered per cycle by a shovel loader comprising a base, a platform supported on the base for rotation relative thereto about a vertical axis, a boom mounted at the lower end on the platform and connected at an upper portion to a stay structure mounted on the platform so the boom extends upwardly and outwardly from the platform, and a bucket supported suspended from the boom and displaceable therefrom in a vertical and horizontal direction, said method comprising determining in the form of an electrical signal the position of the bucket in respect to a selected fixed location in the boom or stay at a plurality of intervals during the rotation of the platform to move the bucket between loaded and unloading positions, determining in the form of an electrical signal the load at a selected fixed location in the boom or said stay structure where the load is related to the mass and position of the bucket and bucket contents, processing said position and load electrical signals for a plurality of interval determinations in an electronic processor to provide a number of mass determinations of the bucket and bucket contents from the interval determinations made during said movement, and averaging said mass determinations to provide a final mass determination of the -19- bucket and bucket contents, v\-cr e oZsr nvj A shovel loader having a bucket supported from a structure, the structure being movable to locate the bucket in respective loaded and unloading positions, ap~paratus for measuring the quantity of material delivered by t he bucket per shovel cycle, said apparatus comprising means to determine the position of the bucket with respect to a selected location in the structure at a plurality of :intervals during said movement of the bucket, means to provide a processable position signal indicative of the determined position of the bucket, means to determine the load at a selected location within the structure where the load is related to the mass of the bucket and bucket **contents at said intervals during said movement of the bucket, means to produce a processable load signal indicative of the determined load at said location, and processing means to receive szid position and load signals for a plurality of interval de te rmi nations and calculate therefrom a number u mas3 determiniztions of the bucket and bucket contents from L. e interval determinations made during said movement, and to average said mass determinations to provide a final mass determination of the bucket and bucket contents, the mass of the employ bucket being subtracted to .0 .oprovide the mass of material delivered.

11. A shovel loader as claimed in claim 10 wherein the means to determine the bucket position is adapted to determine the distance of a fixed point on the bucket from each of two spaced fixed points on the structure, and the position signal producing means produces respective signals indicative of each of said distances for supply to the -@4van s.

12. A shovel loader as claimed in claim 10 or 11 wherein the structure is pivotal about a vertical axis to move the bucket between said loaded and unloading position, and said position and load determining means are operable at preselected intervals during said pivotal movement between said positions in either direction.

13. A shovel loader as claimed in claim 10 wherein, the position determining means and the load determining means are adapted to respectively make bucket position and load first determinations as the bucket moves from the loaded to the unloading position, and second determinations as the bucket moves from the loaded to the unloading position, and second determinations as the bucket moves from the unloading to the loaded position, and said tSer-e O -means determines the average final mass ot the loaded bucket and contents from said first determinations, the average final mass of the unloaded bucket and contents from said second determinations, and the differences between said average final masses.

14. A shovel loader claimed in any one of claims 10 to 13 wherein there is provided means to provide: a processable signal indicative of the velocity and acceleration of the bucket and the structure when the bucket if, moving between the loaded and unloading positions, said processing means being programmed to determine from said signal the kinetic load existing at said fixed location in the structure from the velocity and acceleration of the bucket and str!icture. A shovel loader as claimed in any one of claims to 14 wherein the structure includes a platform, an upwardly extending boom connected at the lower end to the platform, a stay rigidly connected to the playform, and a brace -21J- connecting the upper end of the boom to said stay, said bucket being suspended fromi said boom, and said selected location in the structure being in said stay. DATED this 25th day of August, 1989. ACET LIMITED WATERMARK PATENT ATTORNEYS SUITE 18 159 ADELAIDE TERRACE EAST PERTH WA 6004 *0 A S SOS, S S 0~ d S I S IS S S S AS'S S p 5g. S S #5 S 550555 0 S -1 1 .22/130/CK