FI129572B - Method and system for measuring a load in a bucket of a work machine, and a work machine - Google Patents

Abstract

The invention relates to a method for weighing a load in a bucket (12) of a working machine (14), according to which calibration method is performed in the following steps: (p2) and eccentric third pressure levels (p3) in the different positions of the crane arm (18), and the weighing of the load is performed in the following steps: - the existing load in the bucket (12) is weighed, - during weighing both the position (a1) and position (a2) of the bucket (12), - on the basis of first, second and third pressure levels (p1, p2, p3) the change of the first pressure level (∆p1) is calculated, and on the basis of first, second and third pressure levels (p1, p2 , p3) the change of the second pressure level (∆p2) is calculated, - the change of the second pressure level (∆p2) is scaled, - a first correction value (C1) is calculated by comparing the changes of the first pressure level (∆p1) with the change of the third pressure level (∆p3 ), - one of the asymmetric load (11) o The required second correction value (C2) of the pressure level of the lifting cylinder (21) is calculated by comparing the scaled changes of the lifting cylinder (21) and the bucket cylinder (20) in second pressure level with each other, and - the measured pressure level of the lifting cylinder (22) is corrected to obtain a weighing result corrected by means of said first correction value (C1) and second correction value (C2). The invention also relates to a weighing system.

Description

METHOD AND SYSTEM FOR WEIGHING THE LOAD DURING THE MACHINE

The invention relates to a method for weighing a load in a bucket of a machine, the bucket being articulated to the end of at least one boom and the bucket being operated by a bucket cylinder and the boom by a lifting cylinder, the method comprising calibrating - the pressure levels of the mast cylinder during loading, - the weighing position and the position of the boom are determined, and - the measured pressure level of the lifting cylinder is corrected by a correction value to obtain a corrected weighing result. The invention also relates to a weighing system for a work machine provided with a bucket and a work machine. A load weighing system and method for mounting a load to be mounted on a machine is known from the prior art US 2008319710 A1, wherein the weighing is based on the measurement of the hydraulic pressure from the lifting cylinders of the machine boom. By measuring the pressure, the force on the lifting cylinders can be calculated. In addition to the load in the bucket, this force depends on, among other things, the position of the boom and the tilt of the implement. Although the positions O 25 of the working machine - all moving parts (basic machine, boom and bucket) are measured and the result is compensated accordingly, one important factor in practical work is still overlooked. This factor N is the uneven distribution of the load in the bucket. The position of the load affects the distance of the center of gravity of the load from the point of attachment of the lifting cylinders and thus the force acting on the lifting cylinders 3, even if the position of the bucket is the same or N it is compensated for during weighing. The weighing result is thus dependent on the position of the load center of gravity in the bucket. This is often noticed in work tasks where, for example, the variety to be loaded and especially the grain size of the soil varies greatly during the work.

This creates situations in which the center of gravity of the load in the bucket varies and causes significant errors in the measurement.

A similar weighing system is also available, for example, the Power weighing system manufactured by Tamtron Oy in Finland.

The object of the invention is to provide a more accurate method for weighing a load in connection with a bucket than the prior art methods, which can take into account the effect of the eccentricity of the load on the weighing.

The characteristic features of the present invention appear from the appended claim 1. It is also an object of the invention to provide a more accurate system for weighing a load in connection with a bucket than prior art systems, which can take into account the effect of load eccentricity on weighing.

The characteristic features of the present invention appear from the appended claim 13. It is also an object of the invention to provide a working machine which includes a weighing system more accurate than the prior art machines for weighing a remote load.

The features of the present invention appear from the appended claim 14. The object of the method according to the invention can be achieved by a method for weighing a load in a bucket of an implement, the O 25 bucket being articulated to at least one boom and the bucket being driven by a bucket cylinder and a boom by a lifting cylinder. In this method, calibration, load weighing and weighing correction are performed.

Calibration is performed in the following steps, N to determine the first pressure levels of the bucket cylinder and lift cylinder at different boom positions with the bucket empty N and in the normal position, to determine the bucket cylinder and lift cylinder position corrected second pressure levels with the boom and bucket at different positions, and the bucket with a load whose center of gravity is known, and determining the eccentric third pressure levels of the bucket cylinder and the lift cylinder at different positions of the boom and bucket when the bucket is loaded with an eccentric load whose center of gravity is known. The weighing of the load is performed in the following steps, in which the load in the bucket is weighed by measuring the fourth pressure levels of the bucket cylinder and the lifting cylinder during loading and determining both the position of the boom and the position of the bucket during weighing. In addition, the weighing calculates, based on the first pressure levels, the second pressure levels and the third pressure levels, the first change in pressure level due to bucket position, both for bucket cylinder and lift cylinder, at empty and full bucket, and and in the bucket position, a second change in pressure level due to the asymmetric position of the load in the bucket, which occurs on both the bucket cylinder and the lift cylinder. Further weighing, the second pressure level change is scaled to form a scaled second pressure level change to the load used for calibration, the first correction value due to bucket position is calculated for the lift cylinder pressure level by comparing the first pressure level change with the third pressure level. calculating a second correction value for the asymmetric load on the lift cylinder pressure level by comparing the changes in the scaled second N pressure level of the lift cylinder and the bucket cylinder. Finally, the measured pressure level of the lifting cylinder is corrected by the first correction value and the second N correction value to obtain a corrected weighing result.

The main idea of the invention is based on the finding that the discontinuity of the load can be determined by considering the relationship between the bucket cylinder and lift cylinder pressure levels, which varies depending on the position of the load in the bucket.

For example, in an excavator with the bucket tip pointing toward the excavator, the position of the load in the bucket near the tip produces the highest bucket cylinder pressure when the load is farther from the bucket articulation point to the transfer boom.

Correspondingly, the load located behind the bucket produces the lowest bucket cylinder pressure and the highest lift cylinder pressure.

The invention first determines how much pressure the boom and bucket alone exerts on the lifting cylinder and the bucket cylinder in different positions, after which it is possible to determine how much additional pressure the load can cause.

In addition, it is determined how much the pressure level changes when the load is eccentrically in the bucket.

When these are known, it is possible to deduce from the measured pressures the bucket cylinder and the lifting cylinder whether the load is eccentric and to take this into account in the weighing.

In addition, other factors causing the need for repair can be taken into account in the weighing, such as, for example, the position of the implement on a sloping surface, the transfer speed of the boom. - In this context, the normal position means the position in which the O 25 bucket is held during the normal lifting of the boom. > N Preferably, in calculating the change in the first pressure level, the difference between the first pressure levels and the second pressure levels N is interpolated to all boom positions for both the empty bucket and the full bucket.

With interpolation, calibration does not have to be performed for a huge number of position points, but the intervals between position points can be interpolated while the accuracy remains good.

Preferably, in calculating the change in the second pressure level, the third pressure level is interpolated to all locations of the load in the distance.

Preferably, the interpolation is first order interpolation, i.e. linear interpolation. It has been found that the change in pressure is quite linear between points.

The pressure levels of the former can be determined at a measuring point of 4 to 20 booms, preferably at 8 to 12 measuring points in the operating range of the boom. In this case, a sufficient number of measuring points is obtained to compensate computationally for the measurement errors caused by the insignificant load and the position of the bucket.

Alternatively, first pressure levels of 3 to 6 measuring points can be formed and the intervals between the measuring points are blue-interpolated. In this case, the number of measuring points can be kept smaller and the calibration is faster. On the other hand, the calculation of the first pressure levels by blue interpolation is slightly less accurate than the determination using a larger number of measurement points.

Preferably, the second pressure levels and the third pressure levels are formed in the slowest possible boom movement in which tensioning can be performed. In this case, the acceleration due to the movements of the boom and the error resulting therefrom in the measurement are as small as possible, and the pressure measurement at the measuring points can be performed without stopping the movement of the boom. 05 3 30 Preferably, the fifth pressure levels are determined with the basic machine N in the tilted position and the third correction value caused by the position of the basic machine is calculated for the pressure level of the lifting cylinder as the difference between the first pressure level and the fifth pressure level. In this way, for example, a situation can be taken into account in which the basic machine of the working machine is on an inclined surface and causes an error in the measurement when the center of gravity of the load moves horizontally away from the articulation point of the boom.

According to one embodiment, the method also determines the sixth pressure levels with the boom in lateral movement and calculates a fourth correction value for the lifting cylinder pressure level caused by the lateral movement of the boom as the difference between the first pressure level and the sixth pressure level. This eliminates calculation errors due to lateral movement of the boom.

According to another embodiment, the method determines the seventh pressure levels when the boom is operated by a lifting cylinder and calculates a fifth correction value for the lifting cylinder pressure level caused by the movement of the boom as the difference between the first pressure level and the seventh pressure level. This again makes weighing more reliable.

In one embodiment, the implement is an excavator and the boom includes both a boom and a transfer boom, and both calibration and measurement are performed at all boom and transfer boom positions. In the case of an excavator, the importance of position correction and eccentric load compensation increases as the bucket and its load O 25 are on average farther from the boom articulation point 5 to the basic machine than, for example, bucket loaders with N only a boom with the bucket.

= a ~~ According to one embodiment, the second pressure levels and the third pressure levels are also formed at a measuring point of 4 to 20 booms, preferably at 8 to 12 measuring points in the operating range of the boom. With this N, the weighing accuracy of the method according to the invention can be further specified, because the intervals to be interpolated between the measuring points are shorter than in the embodiment in which the second and third pressure levels are measured only in the boom extremes.

Preferably, the measured values of the boom position are continuously compared with the boom position values contained in the calibration tables formed from the boom-specific first pressure levels, second pressure levels and third pressure levels, and the lifting cylinder pressure value is determined directly from the from the calibration table.

The purpose of the weighing system according to the invention can be achieved by a weighing system for a machine equipped with a bucket, the machine comprising a frame, at least one boom articulated to the bucket to hang the bucket, a bucket-operated bucket cylinder and a boom-operated lifting cylinder and a second pressure sensor for measuring the pressure in the bucket cylinder and generating a second pressure information.

In addition, the system includes a first position sensor for determining the position of the boom and generating the first position information, a second position sensor for determining the position of the bucket and generating the second position information, a central unit comprising a memory unit and 5 software means for performing the weighing calculation and N = don, for transmitting the first position information and the second position information to the central processing unit.

The system stores the first pressure levels of 3 30 bucket cylinders and lifting cylinders in different positions of the boom N when the bucket is empty, the second pressure levels in different positions of the boom and bucket when the bucket is loaded with a known center of gravity, and the third pressure levels in different boom and bucket positions being loaded with an eccentric load whose center of gravity is known.

The software means are adapted to calculate, on the basis of the first pressure levels, the second pressure levels and the third pressure levels, the change in the first pressure level due to the boom position and the bucket position for both the bucket cylinder and the lifting cylinder at empty and full buckets, and to calculate the first pressure levels. based on the levels and the third pressure levels, the change in the second pressure level due to the asymmetrical position of the load in the bucket in the position of the boom and in the position of the bucket, which is caused to both the bucket cylinder and the lifting cylinder.

In addition, the software means is adapted to scale the second pressure level change to form a scaled second pressure level change for the load used to calibrate, calculate the first correction value for the bucket position to the lift cylinder pressure level by comparing the first pressure level change - the second correction value caused by the load on the lifting cylinder pressure level by comparing the changes in the scaled second pressure level of the lifting cylinder and the bucket cylinder.

Furthermore, the software means are adapted to correct the measured pressure level of the lifting cylinder in order to obtain a weighing result corrected by the first correction value and the second correction value.

The method and weighing system according to the invention are particularly suitable for use in an excavator, but also in a wheel loader or telehandler and other similar applications.

The load to be weighed at the place of use may be located at a distance from one, two or even three or more N booms connected to each other, each boom having its own actuator N, measuring its pressure level and measuring the position.

Preferably, the position sensors used in the system are non-contact position sensors, and the position sensors preferably include at least one gyroscope to account for long-term accelerations in the measurement of the position sensors.

In this way, the position measurement can be carried out reliably.

The invention will now be described in detail with reference to the accompanying drawings, which illustrate some embodiments of the invention, in which:

Figure 1 shows a side view of a weighing system according to the invention implemented in connection with an excavator, Figure 2 shows parts of a weighing system in block diagram, Figures 3a and 3b show a problem with weighing an eccentric load in a bucket, Figure 4 shows a side step of a calibration step , with the boom in its innermost position and the bucket in its innermost position, Figure 5 shows a side view of the step of calibrating the method according to the invention with the boom in its innermost position and the bucket in its outermost position. Figure 7 is a side view of the step of calibrating the method of the invention with the boom in its outermost position and the bucket in its outermost position; in its outermost position,

Figure 8 shows the steps of the method according to the invention in block diagram form. Figure 9 shows graphically the table data collected during the calibration drawings.

In Fig. 1, the method and system 10 according to the invention are referred to by describing the invention by means of an embodiment implemented in connection with an excavator 100 operating as a working machine 14. The excavator 100 includes a base machine 102, a boom 18 articulated to the base machine 102 by a first joint 46, which in the excavator 100 consists of a lifting boom 40 and a transfer boom 42 articulated to the lifting boom 40 by a second joint 44. A bucket 12 is articulated to the transfer boom A lifting cylinder 22 is articulated between the lifting boom 40 and the base machine 102, a transfer cylinder 47 between the lifting boom 40 and the transfer boom 42, and a bucket cylinder 20 between the transfer boom 42 and the bucket 12. Preferably, there are two lifting cylinders in parallel. Although the application will hereinafter refer to a single lifting cylinder, it is to be understood that, depending on the application, one, two or more lifting cylinders are required in parallel to provide lifting force. The system 10 includes a first pressure sensor 24 for measuring the pressure of the lift cylinder 22 and generating a first pressure information p01 - and a second pressure sensor 26 for measuring the pressure of the bucket cylinder 20 and generating a second pressure information p2. The system further includes a first position sensor 28 for determining the position of the boom N18 and generating a first position information A1 and a second position sensor 30 for determining the position N of the bucket 12 and generating a second position information a2. Preferably, there are two first pressure sensors if there are two lifting cylinders in parallel. In the case of the excavator, the first position sensor 28 measures the position of the lifting boom 40, and in addition a fourth position sensor 56 is used, which measures the position of the transfer boom 42. Preferably, the system 10 may also include a third position sensor 31 which measures the position of the base 102 of the excavator 100, i.e. the body 16, the cab and the undercarriage of the excavator 100, to detect a possible tilt and generates a third position information a3.

The position sensors used can be, for example, acceleration and tilt sensors. Preferably, at least one of the position sensors is a gyroscope, i.e. a so-called 3D position sensor, which also detects the position during long-term acceleration. The acceleration and position sensors may be, for example, non-contact sensors known from Analog Devices Inc. under the trade name ADIS16209, and the gyroscope used may be, for example, a gyroscope manufactured by STMicroelectronics International N.V. under the trade name XXXYYYY. Preferably, the sensors use a Kalman filter. The position sensors can produce position information 100 to 200 times per second, preferably 130 to 150 times per second. The system 10 further includes, as shown in Figure 2, a central processing unit 32 comprising a memory 34 for storing the above-mentioned pressure and position information, a calculation unit 36 for performing the calculation, and software means 38 for performing the weighing calculation by controlling the calculation unit-36. The central unit 32 can be located, for example, in the frame of the basic machine 102 of the excavator 100, 5 under the lifting boom 40 in the upper carriage 50, as shown in Fig. 1. According to Fig. 2, the N central unit 32 The central unit can be, for example, a Linux or 3 30 android-based PC unit or other similar device that receives the necessary power from the work machine. In addition, the system N10 comprises communication means 45 for transmitting at least the first pressure information p01, the second pressure information p02, the first position information a1 and the second position information a2 to the central processing unit 32. The communication means may be, for example, a CAN bus or other similar communication bus. The pressure sensors can be used with an analog message (4 - 20 mA) or the pressure sensors can be connected directly to the CAN bus. The system 10 preferably also includes a display unit 52 and associated controls 55 located in the cab 54 of the excavator 100 shown in Figure 1 for entering setpoints and displaying weighing results and further processing.

Preferably, the system 10 includes Position Sensors for measuring the position of the base machine 102 of the excavator 100, the lifting boom 40, the transfer boom 42, and the bucket 12. By means of the position sensor 31 of the basic machine 102, the central unit 32 can also determine the position and pivoting movement of the upper carriage 50 of the basic machine 102 of the excavator 100. When the system is set up for operation after installation, it measures the forces acting on the lifting cylinders from all areas of the boom trajectory and stores these in combination with accurate boom position information.

If the method according to the invention is carried out in connection with a wheel loader, the system then also includes a limit switch at the innermost limit of the bucket, mounted on the bucket cylinder. This ensures that the O 25 bucket cylinder does not bottom during the measurement, i.e. does not go completely mechanically to the extreme position.

N = Figure 3a shows a situation where the load 11 is located N near the tip of the bucket 12. The compensation of the center of gravity gl is based on the measurement of the pressures N of the lifting cylinders 22 of the bucket cylinder 20 and the boom 18 and their mutual relation. Figure 3a shows the position of the load center of gravity g in the direction vector F1, the distance of the center of gravity gl from the joint 48 of the bucket 12 on the line A and the force acting on the bucket cylinder 20 with the vector Fs b. 12 joints

48. The greater the distance A, the greater the torque applied to the bucket 12 and the greater the force on the bucket cylinder 20. Correspondingly, the greater the distance A, the smaller the force A acting on the lifting cylinder or lifting cylinders 22 of the boom 18, since the center of gravity of the load 11 is closer to the articulation point 46 of the lifting boom 40 and the torque acting on the lifting boom 40 decreases. All this is important, since the weighing result is formed on the basis of the pressure of the lifting cylinder as in the prior art.

In this case, it is possible to calculate the correction factors C1 and C2 from the ratio of the force of the bucket cylinder 20 to the forces of the lifting cylinders 22, whereby a more accurate weighing result is obtained. During commissioning, a series of calibration movements is performed, in which the system “learns” the effect of the position of the known center of gravity of the load 11 on the forces acting on the bucket cylinder 20 and the lifting cylinders 22. - More specifically, in the pressure measurement of the boom lifting cylinders, the pressure on both the piston and the shaft side is measured in real time, and from these the pressure difference is calculated, which is corrected by the effective areas of the cylinder shaft and the piston side. In this way, the exact force acting on the lifting cylinders is obtained. Correspondingly, the effective pressure of the bucket cylinder or cylinders is measured. This can also be combined with other N measurement data to effectively compensate for the distortion caused by the eccentric load on the pressures of the lifting cylinders and thereby to improve the accuracy of the final measurement result. In addition, the method measures the position of the boom and the bucket in real time. A wheel loader typically has only a lifting boom, an excavator has a transfer boom in addition to the lifting boom. Preferably, the position of the excavator base machine is also measured in order to compensate for the resulting measurement error.

The method according to the invention can be divided into two main steps, the first being the system calibration step 200 and the second measuring step 202 shown in Figure 8. Next, a preferred embodiment of the method and its operation in an excavator will be discussed, but the same method the boom is one-piece. During calibration, the system stores information about the lift cylinder and bucket cylinder pressures relative to the boom and bucket position. In connection with the excavator 100, the boom 18 is formed by a lifting boom 40 and a transfer boom 42 as shown in Figures 1 and 3a-7. The baseline excitation can be roughly divided into three basic parts, the storage of baseline pressure curves p1 shown in step 204 of Fig. 8, the storage of bucket position compensation curves p2 shown in step 206 and the third storing p3 in memory 34. S 25 5 In recording the basic pressure curves in step 204, N is first marked with the desired boom area. In this case, the area = preferably means the area of the boom path within which it is desired that load weighing is possible. 3 30 In the case of an excavator, N lifting points are marked on the lifting boom, in the ascending order N from the desired number, from 4 to 20, preferably from 8 to 12. For example, points are marked every 10 to 15 degrees and are stored in the LiftAngleBins [LiftP] table in the CPU's memory. The desired area of the transfer boom is then marked, starting from the innermost desired position of the transfer boom as well as with the lifting boom. The boom positions are marked in the ArmAngleBins [ArmP] table. In this context, the storage of values always refers to the storage of values in the memory of the central processing unit, unless otherwise indicated. After marking the boom position points, basic calibration lifts are performed from the bottom up at a slow speed at each marked boom position. This is done first with an empty bucket and then with a full load with the bucket in the so-called normal position, i.e. the O position. The lifting cylinder pressure measurements measured during empty bucket lifts are stored in the ZeroMapPressure [ArmP] [LiftP] table, the boom positions are the row indices and the boom positions are the column indices. The corresponding measurements for full load lifts are stored in the LoadMapPressure [ArmP] [LiftP] table. During lifting, the bucket cylinder pressure measurements are also stored in the BucketZeroPress [ArmP] [LiftP] table for the empty bucket and the BucketLoadPress [ArmP] [LiftP] table for the full load, respectively. During basic calibration lifts - the bucket positions during the lifts are also stored in the O 25 BucketNPos [ArmP] [LiftP] table. These are the so-called 5 bucket normal positions for each N position of the lifting and transfer boom. Here, the normal position means the position = in which the bucket is generally held in the N position of the lifting and transfer boom in question. That is, in step 204 of Fig. 8, the first pressure levels p1 shown in Fig. 2 are formed.

S Thus, after step 204 in Fig. 8, it is known what pressure levels the lifting and bucket cylinders obtain at any of the operating points of the lifting boom and the transfer boom in the selected operating range with the bucket in the normal position. The operating range selected in this context refers to the area from one end of the measuring points to the other.

In step 206, the bucket position compensation curves are stored in the memory for the empty and full buckets separately. This is done by first making two calibration lifts with an empty bucket at the innermost position of the transfer boom. During the first lift, the bucket is turned to the largest or innermost desired position during lifting. Figure 4 illustrates this position of the bucket and transfer boom. During the second lift, the bucket is turned to the outermost position, as shown in Fig. 5. Figures 4 to 7 show the different positions of the boom 18 of the boom 18 and the transfer boom 42 and the bucket 12 during calibration. The same images are used as an example of the positions of the boom 18 and the bucket 12, whether the bucket is full or empty.

In step 208 of Figure 8, during lifting, these real-time bucket positions are measured and stored on the first lift in the Bucket InPosArmIinPos [Lift Pos] table in the indices indicated by the lifting boom position. The difference between the measured pressure values of the lifting cylinders and the corresponding lifting values of the bucket in the normal position is stored in the O 25 BucketInPosArmInPosLiftDAdcEmpty [Lift Pos] table 5, respectively. Bucket cylinder corresponding values in the N Bucket InPosArmInnerPosBucketDAdcEmpty [Lift Pos] table. = With the second lift, the bucket is kept in the outermost N desired position during the lift and the corresponding measurements are stored in the tables BucketOutPosArmInPos [Lift Pos], N BucketOutPosArmInPosLiftDAdcEmpty [Lift Pos] and N BucketOutPosArmInPosBucketDAdcEmp Next, move the transfer boom to the next position point and perform the same lifts until the lifts are completed in all boom positions. Next, make the corresponding lifts with the empty bucket in the outermost position of the transfer boom in step 210. During the first lift, the bucket 12 is held in the innermost desired position as shown in Figure 6 and the measurements are stored in the tables BucketInPosArmOutPos [LiftPos] (bucket positions) ) and Bucket InPosArmOutPosBucketDAdcEmpty [LiftPos] (corresponding bucket cylinder values). In step 212, the next lift is performed in the same position of the transfer boom as the bucket is out of the desired basic position during the lift as shown in Fig. 7. The corresponding values are stored in the following tables: BucketOutPosArmOutPos [LiftPos], BucketOutPosArmOutPosLiftDAdcEmpty [LiftPos] and BucketOutPosArmOutPosBucketDAdcEmpty [LiftPos]. Next, in step 214 of Fig. 8, the same lifts are performed at the same slow speed as before for the bucket position compensation curves with an empty bucket but at full load. The aim is to keep the bucket in exactly the same position as in the previous - empty bucket lifts during each lift. To this end, the user can be instructed via the user interface to maintain the correct position 5. The mass in the bucket and the placement of the mass N are exactly the same as in the basic calibration lifts of step 204. = The corresponding values are stored in the following tables: N Bucket InPosArmInPosLiftDAdcFull [LiftPos] and 3 30 BucketInPosArmInPosBucketDAdcFull [LiftPos].

S For the next lift, place the bucket in its outer position in the following tables: Bucket OutPosArmInPosLiftDAdcFull [LiftPos] and

Bucket Out PosArmInPosBucketDAdc Full [LiftPos]. Next lift the transfer boom in its outermost position, first bucket in the inside position in the following tables: Bucket Inposarmoutposliftdadcfull [Liftpos] and buckket inposarmoutposbucketdadcfull [Liftpos |], and then in the outermost position to the following tables: Bucket out plyarmoutposppostus. Thus, in step 206, comparative pressure values have been generated with respect to the calibration of the home position at different bucket positions for all different positions of the transfer boom and lift boom with both empty and full buckets, whereby the importance of the bucket position for weighing can be compensated. That is, in step 206, second pressure levels p2 are formed. In the third step, i.e. step 216, the effect of the eccentricity of the load is recorded, i.e. the third pressure levels p3 are determined. The eccentricity detection is based on measuring the change in the pressure ratio between the lifting cylinders and the bucket cylinders, from which the effects of the boom and bucket position are first compensated. After this, O 25 remains two things that affect this pressure ratio - the magnitude of the load 5 and the eccentricity of the load.

N = This step is performed similarly to the position compensation of bucket N in step 206, but now a load of 3 30 is placed in the bucket eccentrically on the tip of the bucket. This mass need not N be the same as that used for the basic calibration, as long as N is known and its center of gravity is known. In addition, the difference to step 206 is that an additional lift is made with the bucket in exactly the same position throughout the lift.

(normal position) as it was in the basic calibration. That is, three lifts are performed with the transfer boom in its innermost position and the other three lifts in the outermost position of the transfer boom. First turn the bucket to its innermost position, then to its normal position, and finally to its outermost position during lifting. With all lifts, the bucket is equally eccentrically loaded. The system instructs the user to keep the bucket in the correct position with each lift.

During lifting movements, the pressure of the lifting cylinders and bucket cylinders is measured in order to determine the pressure differences between the lifting cylinders and the bucket cylinders in relation to the situation where the same load would be placed symmetrically in the bucket. This can be done in two ways, either by two lifts at each bucket position, the first load placed symmetrically (as in the basic calibration) on the bucket and the second lift on the bucket tip asymmetrically. In that case, there would be twice the number of withdrawals. Another option is to make lifts with only an asymmetrical load. In this case, however, it is necessary to determine, on the basis of the basic calibration data, what the pressure values of the lifting cylinders and bucket cylinders would be if the same load were placed symmetrically, as the load now used is not necessarily the same as in the basic calibration.

> N More specifically, in step 216, step 218 is first performed, = where the first lifting with an eccentric load is performed N by holding the bucket in the innermost position during lifting. The first series of 3 30 three lifts is thus performed in the internal position of the transfer boom, N, whereby the pressure N corresponding to the symmetrical load of the lifting cylinders for each position of the lifting boom is obtained as follows:

{((LoadMapPressure [0] [LiftP] + BucketinPosArmInPosLiftDAdcFull [LiftP]) - (ZeroMapPressure [0] [Lif tp] + BucketinPosArmInPosLiftDAdcEmpty [LiftP]))} KalK g xPPKG + [ZeroMapP [ |) = LiftPSym where PPKG is the mass in kilograms to be used in this calibration step and KalKg is the mass symmetrically placed in the bucket for the basic calibration. LiftPSym is the pressure in the lifting cylinder if the load were placed symmetrically, as in the basic calibration. The differential pressure of the boom cylinder compared to the symmetrical load is recorded during lifting for each boom position as follows: BucketInPosArmInPosLiftDAdcPPKG [LiftPos | = LiftP - LiftPSym, where LiftP is the real-time pressure measurement value of the lift cylinder. During the lifting movement, the corresponding pressure difference for the bucket cylinder is also calculated: ((((BucketLoadPress [| 0] [LiftP | + BucketInPosArmInPosBucketDAdcFull [LiftP]) - (BucketZeroPress [O] [Liftp] + BucketInPosArmInPosBucketDA [0] [Liftp] + N BucketInPosArmInPosBucketDAdcEmpty [LiftP]) = BkPSym, where BkPSym is the pressure of the B bucket cylinder for that symmetrically placed N load. The pressure difference of the bucket cylinder compared to the symmetrical load E 25 is recorded during lifting for each position of the lifting boom 5 as follows:

D O BucketInPosArmInPosBkDAdcPPKG | LiftPos] = BkPress - BkPSym, where BkPress is the real-time pressure value of the bucket cylinder.

In step 220, lifting is performed while maintaining the bucket in the normal position as well as in the basic calibration. The lifting pressure corresponding to the symmetrical load for each boom position is obtained as follows: (LoadMapPressure [0] [Lif tP] - ZeroMapPressure [0] [Liftp |) PPKG _— x KalKg + ZeroMapPressure | 0] [Liftp | = LiftPSym continued: BucketNormPosArmInPosLiftDAdcPPKG [LiftPos] = Lif tP - LiftPSym and for bucket cylinder equivalent: (BucketLoadPress [0] [LiftP] - BucketZeroPress [0] [Liftp]) PPKG _— "" "" "" 9Tm91n ] [Liftp] = BkPSym BucketNormPosArmlInPosBkDAdcPPKGI | LiftPos | = BkPress - BkPSym In step 222, lift the bucket in the outermost position during lifting, the pressure corresponding to the symmetrical load: {((LoadMapPressure [0] [LiftP] + BucketOutPosArmiInPosLiftDAdcFull [LiftP]) N - (ZeroMapPressp [0] B ]))} N KalKg <Q xPPKG + (ZeroMapPressure [| 0] [Liftp]

N N + BucketOutPosArmInPosLiftDAdcEmpty [LiftP]) = LiftPSym

I = 25> BucketOutPosArmInPosLiftDAdcPPKG [LiftPos] = LiftP - LiftPSym

D

N S and for bucket cylinder:

(((BucketLoadPress [| 0] [LiftP] + BucketOutPosArminPosBucketDAdcFull [LiftP]) - (BucketZeroPress [0] [Lif tp] + BucketOutPosArminPosBucketDAdcEmpty [LiftP])] KalK g xPPK + ( LiftP]) = BkPSym BucketOutPosArmInPosBkDAdcPPKG [LiftPos | = BkPress - BkPSym. According to one embodiment, the bucket position-corrected second pressure levels p2 determined in step 206 and the third asymmetric load p3 pressure levels of step 216 may also be determined by performing pressure measurements instead of the outermost and innermost positions of the boom preferably at 8 to 12 measuring points, which also include the above-mentioned boom and bucket extreme positions and the bucket normal position. This provides a more accurate calibration.

S <Figure 9 shows, at a general level, the table data collected during the calibration lifts 7 25. The table shows the measured value for each - lift and transfer boom position set, which E depends on the boom position. This value can be the bucket position during basic calibration S, ie basic position (BucketNPos [] []), inner = bucket position (Bucket InPos [] []), outer bucket position a 30 (BucketOutPos [] []), lifting cylinder pressure during basic calibration with load ( LoadMapPressure [] []), etc. All tables are preferably similar, X-axis boom position, Z-

on the shaft, the position of the lifting boom and the third, Y-dimension are the values measured during the calibration phase corresponding to these positions. Figure 9 illustrates a situation where the position of the lifting boom is between 8000 ... 8400 and the position of the transfer boom between

6000 ... 6500. X1Lift and X2Lift are index indicators in the value table and show the indices in the table in Figure 9 for the boom and X1Arm and X2Arm for the transfer boom. The values of the index indicators are obtained by continuously comparing the measured values of the boom position with the boom position point values contained in the boom-specific look-up tables. In the value table, the values corresponding to the boom position are in the same indices as in the search table, eg the value corresponding to boom position 8400 and transfer boom position 6500 can be found in the value table under [1] [1] (Boom index 1, boom index 1). For example, in the case of Figure 9, the boom lookup table values: Index 0: 8000, index 1: 8400, index 2: 8900, index 3: 9400,, ... etc, and the boom lookup table values: 7000, 6500, 6000, 5500, 5200, 5000 , etc. In the case of Figure 9, the values of the index pointers are - the following: S 25

N 5 = XILift = 0 N - X2Lift = 1 = = X1Arm = 2 a 3. X2Arm = 1

O N In the calculation routines, the values Y1.1 (2900) and Y1.2 (3000) in the value table and Y2.1 (3120) and Y2.2 (3200) in the value table are first calculated with respect to the boom position. From these, the final value with respect to the position of the transfer boom is still calculated. The method can be any curve fitting method, in the example simple linear interpolation has been used.

When simplified, the boom position is continuously measured and the value stored in the calibration corresponding to the position is retrieved from the value table and the exact value corresponding to the prevailing boom position is calculated between the value points in the value table.

As can be seen from Figures 4 to 7, the position of the bucket relative to the rest of the boom is constantly changing according to the position of the boom.

Therefore, bucket position maps measured during calibration for the basic position and the inside and outside positions over the entire boom area are required.

Similarly, the pressure values of the lift cylinder and bucket cylinders change depending on the position of the boom and bucket, so corresponding tables are also required for them.

Next, the sections of the measurement step 202 will be described in more detail.

During weighing, the central unit knows the real-time bucket position information a2 (BucketPos) obtained from the second position sensor, as well as the bucket position stored in memory during each possible boom and transfer boom position (BucketPosNorm). This is calculated by interpolating from the basic calibration graph O 25 (BucketNPos [ArmP] [LiftP] table) according to the boom position. The weighing 5 according to the method is performed while the boom is in motion, whereby no extra time is required for the N weighing, but it can be performed E while working. 05 3 30 The following are the N input data used in the measurement and their abbreviation.

Of the N abbreviations used in the measurement, LiftPos is the real-time boom position information al.1 (typically a value between 1000 and 14000), LiftAngleBins [Lift Pos] is the number of boom positions stored in the table, for example 8 (Lift Pos = 8). In addition, the abbreviation Bucket InPosArmInnerPos [Lift Pos] stores the maximum (innermost) position values of the bucket in the table with the transfer boom in the innermost position, for each boom position (e.g.

Lift Pos = 8 pcs). Further, the abbreviation Bucket InPosArmOuterPos [Lift Pos] is the maximum (innermost) bucket position values stored in the table with the transfer boom in its outer position, for each lift boom position (eg Lift Pos = 8 pcs.). The table may be a table similar to Figure 9.

The position of the bucket must also be taken into account in the calculation, as the position has a large effect on the pressure of both the lifting cylinder and the bucket cylinder in addition to the load and its location.

The so-called bucket. the normal position is the position used in the basic calibration lifts and at the same time the zero point, on both sides of which the compensation values are also calculated according to the position of the bucket.

The following is a situation where the position of the bucket is greater than or equal to the basic position of the bucket.

If the bucket position is smaller than the normal position, the calculation is performed in exactly the same way, but with the setpoints corresponding to this bucket position range. - The purpose of the calculations (up to step 242) is to determine the pressure of the 5 bucket cylinders using the O 25 calibration data and measurements if the load were in the bucket N symmetrically (BucketAdcIfSymLoad), ie as in the E basic calibration.

In other words, the fourth = pressure levels p4 and the change in the first pressure level (Apl) are determined. It is then possible to calculate from the center of gravity calibration data N (to compensate for any uneven load distribution) N a second correction value C2 for the force (pressure) on the lifting cylinder. Finally, the error caused by the position of the bucket can be compensated to the pressure of the lifting cylinder by means of a correction value C2. In the next step 224, the bucket is in the innermost position, i.e., BucketPos> = BucketPosNorm. In this case, calculate from the calibration data what is the largest or innermost position of the bucket used in the calibration phase instead of the boom and transfer boom: (BucketInPosArmInnerPos [X21; ge] - BucketInPosArmInnerPos [X11; g +]) LiftP + ( ]) (Lif - LiftAngleBins [X11 ;; e]) + BucketInPosArmInnerPos [X1:; pe] = Yl (BucketInPosArmOuterPos [X2: ;; pi] - BucketInPosArmOuterPos [X1:; re]) Liftp —_— FX XX XX XX XX + (Lif tPos (LiftAngleBins [X20] - LiftAngleBins [X Trigel) (Lif - LiftAngleBins [X1:; pe]) + BucketInPosArmOuterPos [X1:; pe] = YZ (rz) ArmAngleBins [0 - =: = "-« ( ArmAngleBins (ArmAngleBins [0] - ArmAngleBins | ArmPosSize - 1]) (g [0] - ArmPos) + Y1 = InnestBucketPos where InnestBucketPos is the largest (innermost) bucket position used in the bucket position calibration for the boom and transfer boom in question.

N e Next, in step 226, the difference in pressure of the lift cylinder with the empty bucket is calculated from the calibration data with the bucket N in its innermost position compared to the pressure of the lift cylinder I 25 in the basic calibration, where the bucket is a N in the normal position: 00

O 0 N (BucketInPosArmlnrPosLiftDAdcEmpty | X21ge] - N BucketInPosArmlnPosLif tDAdcEmpty [X11: st]) Liftp = 1 = r1111111211123301l211—— + + Uljitos (LiftAngleBins [X2, ;;] - .])

+ BucketInPosArmlnPosLiftDAdcEmpty [X1: ipe] = Yl (BucketInPosArmOutPosLif tDAdcEmpty | X21; ge] - BucketInPosArmOutPosLiftDAdcEmpty [X1:; Re]) LiftP - LL * (Lif tA tAngleBins [X11st]) + BucketInPosArmOuterPosLif tAdcEmpty | X1:; pe] = YZ eth - - (armAngleBins [0] - ArmAngleBins | ArmPosSize - 1]) (ArmAngleBins | 0] - InnPos) + InnPestB + the difference in pressure of the lifting cylinder with the bucket when the bucket is in its innermost position compared to the normal position of the bucket in those lifting boom and lifting cylinder positions. in the inner position and decreases when moving outwards.

In step 228, the same calculation is performed for the full bucket.

O

N 5 (BucketInPosArmlnPosLiftDAdcFull [X21; ge] - | BucketInPosArminPosLiftDAdcFull | X1 ;; N _BucketinPosArminPostif (DAGCTul lus); epg - (LiftAngleBins [X2, ;;:] - [Lif XAngB] X1:; st])

K 3 25 N + BucketinPosArmInPosLiftDAdcFull [X16] = YI

OF

(BucketInPosArmOutPosLif tDAdcFull [X21; ee] - BucketInPosArmOutPosLiftDAdcFull [X1:; re]). St (Lif tPos (Lif tangleBins [X2, ;; e] - Lif tAngleBins [X1:; gt]) - Lif tAngleBins [X 11ise]) + BucketinPosArmOutPosLif tDAdcp ,; [X 1p] = YZ Wee) (trmangleBins [0 * (ArmAngleBins [0] - ArmAngleBins [ArmPosSize - 1]) (ArmAngleBins | 0] - ArmPos) + Y1 = InnestBucketPosLiftDAdcFull where InnestBucketPosLiftDAdcFull is in to the corresponding bucket cylinder pressure with the bucket in its normal position (throughout the range of travel of the lift cylinder and bucket cylinder).

In step 230, the same is calculated for the bucket cylinder pressure: [(BucketInPosArmInPosBucketDAdcEmpty [X21; rc] —-BucketInPosArmInPosBucketDAdcEmpty [X11; re])] LiftP (Lif tAngleBins [X 2c] - Lif XAgleB <+ BucketInPosArmInPosBucketDAdcEmpty [X1:; pe] = YI oO

N - (BucketInPosArmOutPosBucketDAdcEmpty [X2: ipt] i —BucketPosArmOutPosBucketDAdcEmpty [X1yy.]) LiftP IS (LiftAngleBins [X2ur. - LiftängleBins [X1yc) - 15

O D - LiftAngleBins [X1 ¢])

N | 25 + BucketInPosArmOutPosBucketDAdcEmpty [X1:; pe] = YZ eth - - (armangleBinsjo * (ArmAngleBins [0] - ArmAngleBins | ArmPosSize - 1]) (ArmAngleBins | 0] - InnPDABc) the difference when the bucket is in its innermost position compared to the corresponding bucket cylinder pressure with the bucket in its normal position (throughout the range of travel of the boom and transfer boom).

Further, in step 232, the same is calculated for the full bucket: (BucketInPosArmInPosBucketDAdcFulllX2:; rc] —-BucketInPosArmInPosBucketDAdcFull [X1:; re]) LiftP s ..1 '".- IaAUauÖ = w =' i" i'as! 'M0 ; €] 3]?); ”! m! I /. J. '”Bj” MÖuu m. Rr .... Rm ik (LiftAngleBins [X2,; p:] - LiftangleBins [X11: 5+]) (LiftPos - LiftAngleBins [X1y.]) + BucketInPosArmInPosBucketDAdcFull [X1lift] = Y1 (BucketInPosArmOutPosBucketD AdF2 ]) LiftP eee 3. (LiftAngleBins [X2,; p:] - Lif tAngleBins [X 1,7.) (LiftPos - LiftAngleBins [X1y.]) N 20 & 2 + BucketinPosArmOutPosBucketDAdcFull [X 1p] = Y2 oO

OF

N Zz MT - (armangleBinsjo * a (ArmAngleBins [0] - ArmAngleBins | ArmPosSize - 1]) (ArmAngleBins | 0] bo - ArmPos) + Y1 = InnestBucketPosBucketDAdcFull

O 2 25

N Q where InnestBucketPosBucketDAdcFull is the bucket cylinder pressure difference at full bucket when the bucket is in its innermost position compared to the corresponding bucket cylinder pressure when the bucket is in its normal position (throughout the boom and transfer boom travel paths). After the differential pressure calculations in steps 224 to 232, the differential pressure of the lift cylinder relative to the bucket position is interpolated to the empty bucket (i.e., the difference in the bucket position during measurement from the normal bucket position): InnestBucketPosLiftDAdcEmpty «(BucketPos - BucketPos - the difference in pressure of the lifting cylinder with respect to the position of the bucket for the full bucket (i.e. the difference in the position of the bucket at the time of measurement compared with the normal position of the bucket). InnestBucketPosLiftDAdcFull «(BucketPos - BucketPosNorm) (InnestBucketPos - BucketPosNorm) = LiftAdcDeltaFToBucketNormPos Further, in step 238, the bucket cylinder pressure difference from the normal bucket position to the bucket during the bucket is interpolated (difference during measurement). > (InnestBucketPosBucketDAdcEmpty) «(BucketPos - BucketPosNorm) N (InnestBucketPos - BucketPosNorm) - 25 = BucketAdcDeltaEToBucketNormPos a.

InnestBucketPosBucketDAdcFull (InnestBucketPos — BucketPosNorm) * (BucketPos — BucketPosNorm) = BucketAdcDeltaFToBucketNormPos Nostosylinterin ja kauhasylinterin paine-erojen interpoloinnin jälkeen vaiheessa 242 lasketaan mikä olisi kauhasylinterin paine, jos kuorma olisi symmetrisesti kuten peruskalibroinnissa: ((BucketAdcDeltaFToBucketNormPos + LoadMapBucketPressure) —(BucketAdcDeltaEToBucketNormPos + ZeroMapBucketPressure)) ((Lif t AdcDeltaFT oBucketNormPos + LoadMapPressure) —(LiftAdcDeltaEToBucketNormPos + ZeroMapPressure)) x(LiftAdc — (Lif tAdcDeltaEToBucketNormPos + ZeroMapPressure)) + (BucketAdcDeltaEToBucketNormPos + ZeroMapBucketPressure) ' = BucketAdcIf SymLoad missä Bucket AdcIfSymLoad on kauhasylinterin paine, jos nostosylinterin paineen mukainen kuorma on in the bucket symmetrically.

This was calculated from the bucket position compensated lift cylinder pressure.

The value of BucketAdcIfSymLoad is needed later in step 260 to calculate the error correction value caused by the load center of gravity for the lift cylinder pressure. = LoadMapBucketPressure is the bucket cylinder pressure N in the basic calibration, where the bucket is in the normal position and the load is 5 symmetrically.

LoadMapPressure is the corresponding lift cylinder N pressure, ZeroMapBucketPressure and ZeroMapPressure are respectively E 25 lift cylinder pressure without load, with an empty bucket. 5 3 Next, with respect to the position 3 of the lifting and transfer booms, the change in the pressure of the lifting cylinder caused by the transfer of the calibration weight (PPKG) from the center of the bucket to the tip is interpolated from the bucket center of gravity calibration data.

In other words, a second change in pressure levels Ap2 is determined. In step 244, interpolation is performed to the normal position of the bucket over the entire area of the lifting and transfer boom: (BucketNormPosArmlnPosLiftDAdcPPKG [X21; gt —BucketNormPosArmInPosLiftDAdcPPK7 [ - Lif tängleBins | X1:; gt]) + BucketNormPosArmlnPosLiftDAdcPPKG [X1: ge] = YI (BucketNormPosArmOutPosLif tDAdcPPKG [X2:; gt] -BucketNormPosArmoOutPosLif tDAP) [X 1,7.) + (LiftPos - LiftAngleBins [X1y.]) - + BucketNormPosArmOutPosLif tDAdcPPKG [X1,:; pe] = YZ <NI —.—.) (Armanglenins [o * (ArmAngleBins [0] - ArmAngleBins | ArmPosSize - 1]) (ArmAngleBins | 0] - ArmPos) + Y1 = BucketNormPosLiftDadcPPKG S 20 In step 246 for the bucket's innermost (largest) position:

N> N (BucketInPosArmInPosLiftDAdcPPKG [X25] - —-BucketInPosArmlnPosLiftDAdcPPKG [X11; se]) LiftP _—% z (LiftAngleBins [X2urc] - LiftAngleBins [X1yrc]) [LiftPos & - Lif]

D

N N 25 - + BucketInPosArmlnPosLif tDAdcPPKG [X1:; pe] = Yl

(BucketInPosArmOutPosLif tDAdcPPKG [X21; gt] —-BucketInPosArmOutPosLiftDAdcPPKG [X1:; re]) LiftP (LiftAngleBins [X2,; p:] - LiftangleBins [X1 :: r:]) - (LiftPos tDAdcPPKG [X1:; pe] = YZ (rz) ArmAngleBins [0 —e— —r—— = com * (ArmAngleBins [0] - ArmAngleBins [ArmPosSize - 1]) (ArmAngleBins [0] - ArmPos) + Y1 = BucketInPosLif tDadcPPKG Vaiheessa 248 interpoloidaan edellisistä tuloksista kauhan asennon suhteen: (BucketInPosLif tDadcPPKG-BucketNormPosLif tDadcPPKG) « (BucketPos BucketPosNorm) (InnestBucketPos-BucketPosNorm) +BucketNormPosLiftDadcPPKG = Lif tDadcPPKG Seuraavaksi interpoloidaan nosto- ja siirtopuomien aseman suhteen kauhan painopistekalibroinnin tiedoista kauhasylinterin paineen muutos, minkä on aiheuttanut transferring the calibration weight (PPKG) from the center of the bucket to the tip. a N In step 250, interpolation is performed to the normal position of bucket O:

K

N E (BucketNormPosArmInPosBKDAdcPPKG [| X2: igt N —BucketNormPosArmInPosBkDAdcPPKG [X1f.]). 00 235 «(Lif tPos> (Lif tangleBins [X2, ;;] - Lif tAngleBins [X1:; rt]) 3 - LiftAngleBins [X1ur:]) + BucketNormPosArmInPosBkDAdcPPKG [X1:; ge] = Y1

(BucketNormPosArmOutPosBkDAdcPPKG [X21; rt] —-BucketNormPosArmOutPosBkDAdcPPKG [X11; st]) LiftP (LiftAngleBins [X2urc] - Lif tangleBins [X1: re]) = Y2 + 0 —.— (armangleBinsjo * (ArmAngleBins [0] - ArmAngleBins | ArmPosSize - 1]) (ArmAngleBins | 0] - ArmPos) + Y1 = BucketNormPosBkDadcPPKG In step 252 for bucket's innermost position: gt] —-BucketInPosArmInPosBkDAdcPPKG [X11; st]) | —11111111——1—1 ". ]) - + BucketInPosArmInPosBkDAdcPPKG [X1:; pe] = YI (BucketInPosArmOutPosBkDAdcPPKG [X21; p] --BucketInPosArmOutPosBkDAdcPPKG [X11; st]) | X2, ;; e] - Lif tAngleBins [X1:; gt]) N - Lif tAngleBins [X1:; gt])

N 7 20 - + BucketInPosArmOutPosBkDAdcPPKG [X1:; pe] = YZ

OF

I Ao U wee) -) (armanglenins [o * 5 (ArmAngleBins [0] - ArmAngleBins [ArmPosSize - 1]) (ArmAngleBins [0]

O 2 - ArmPos) + Y1 = BucketInPosBkDadcPPKG

S

N In step 254, the bucket position is interpolated from the previous results:

BucketInPosBkDadcPPKG-BucketNormPosBkDadcPPKG (InnestBucketPos-BucketPosNorm) + BucketNormPosBkDadcPPKG = BucketDadcPPKG Center of gravity calibration is possible with a different load than the actual basic The PPKG value is the mass used in the center of gravity calibration. At a given bucket position and at a given lifting and transfer boom position, the pressure change caused by the change in center of gravity behaves linearly with both the lifting cylinders and the bucket cylinders. In step 256, the values for the full load (for the load used in the basic calibration) are scaled: BucketDadcPPFull BucketDadcPPKG Calk ucketDadc ull = .s - <Ca PPKG g LiptDadcPPPull = "! PUAPPKE Carr l aac ull = ——— In other words, the scaled change in the second pressure level sAp2 is calculated.

In step 258, the magnitude of the lift cylinder due to the change in center of gravity load is calculated.

N S pressure change and corresponding bucket cylinder pressure change:> N Lif tDadcPPFull 2 An r? ((LiftAdcDeltaFToBucketNormPos + LoadMapPressure) = - (LiftAdcDeltaEToBucketNormPos + ZeroMapPressure))

N 3 2 x (LiftAdc - (LiftAdcDeltaEToBucketNormPos + ZeroMapPressure)) = LiftDadc

S

N BucketDadcPPFull ((Lif tAdcDeltaFToBucketNormPos + LoadMapPressure) - (LiftAdcDeltaEToBucketNormPos + ZeroMapPressure))

x (Lift Adc - (Lif tAdcDeltaEToBucketNormPos + ZeroMapPressure)) = BucketDadc where LiftDadc is the change in pressure of the lifting cylinder due to the change in load center load and BucketDadc is the change in pressure in the bucket cylinder resulting from the same change. In step 260, the center of gravity error correction value for the lift cylinder pressure is calculated: _LiftDade * (BucketAdc - BucketAdclfSymLoad) = LiftPressPPCorr BucketDadc - LiftAdcC = LiftAdc + LiftPressPPCorr where BucketAdc is real time LiftAdcC is the measured pressure value of the lifting cylinder, from which the error caused by the center of gravity of the load has been compensated. In step 262, the error correction value caused by the bucket position is calculated for the lift cylinder pressure. Proportion of payload S in the bucket:

I K (Lift AdcDeltaFToBucketNormPos - Lif tAdcDeltaEToBucketNormPos) - (LoadMapPressure - ZeroMapPressure) E * (Based on Lif tAdcC - ZeroMapPressure) = LiftPressLCorr with LiftDressB the mass of the load can be determined. LiftAdcDeltaEToBucketNormPos is the bucket position error compensation for the empty bucket (calculated in step 234), the LiftPressLCorr load part and the LiftAdcC center of gravity compensated base value. In this example, the first correction factor C1 for bucket position correction is formed by LiftAdcDeltaEToBucketNormPos and LiftPresslCorr together, and the second correction factor C2 for bucket load eccentricity is formed by LiftAdcC.

The final corrected weighing result is obtained by calculating the other correction factors for the pressure of the lifting cylinders. These can be the lifting speed and acceleration as well as the error correction value due to the position of the basic machine. In addition, the excavator calculates a correction factor for the turning movement of the boom, because the turning speed of the boom affects the central force acting on the load and thus also the force acting on the lifting cylinders.

The correction of the error caused by the lifting speed can be performed with the formula LiftPress = LiftPress + LiftSpeedEff, where LiftSpeedEff is the error due to the lifting speed. The value is calculated from the calibration values measured at different boom speeds during the calibration phase. S 25 5 The error caused by the lifting acceleration can be corrected by the formula N: LiftPress = LiftPress + LiftAcEff, where LiftAcEff = is the error caused by the change in the lifting acceleration, ie the boom speed. This can be calculated from the calibration values measured with the boom acceleration known in the calibration.

S In addition to correcting the error caused by the acceleration of the boom, the error correction of the acceleration caused by the movement of the basic machine on the load can also be used by the following formula:

LiftPress = LiftPress + LoadAcEff, where LoadAcEff is an error caused by the acceleration caused by the movement of the base machine, which occurs, for example, when driving on uneven ground. This is calculated based on the measurements of the acceleration sensor contained in the bucket position sensor. The correction of the error due to the longitudinal tilt of the basic machine can be performed with the following formula LiftPress = LiftPress + YangleEff * sin (a), where YangleEff is the value corresponding to the position of the boom curve tied to the boom position measured during calibration. The coefficient curve contains its own coefficient for each boom position. The coefficients of the coefficient curve have been measured in the calibration in both directions, for tilting in the direction of the lifting boom and in the opposite direction. The variable a in the blue expression is the longitudinal tilt angle of the basic machine in radians. The odds are for an empty bucket and a loaded bucket separately. In addition to the correction for the error due to longitudinal tilt, the correction for the error due to lateral tilt can also be used with the following formula: LiftPress = LiftPress + XangleEff * sin (b), where XangleEff is the coefficient for lateral tilt measured in the calibration. The variable b of the blue expression is N is the lateral tilt angle in radians. S 25 5 The error correction for boom rotation speed 0 can be performed with the formula LiftPress = LiftPress + SwEff, where SwEff = is the correction value calculated N based on the calibration data and the measured rotation speed. S 30

O N The final weighing result can be calculated with the following N formula: KalKg / ((LoadMapPressure-ZeroMapPressure)) * (LiftPress-ZeroMapPressure) = WeighResultKG where WeighResultKG is the finished measurement result. A version of the method according to the invention has been presented above, in which the position and center of gravity calibration of the bucket is performed only at two points of the transfer boom, i.e. in the inner position and in the outer position. The most common method is exactly the same with the exception that all lifts are made at each boom position. In this case, the only difference is in the available tables, for example the table Bucket InPosArmInPosLiftDAdcFull [LiftPos] changes to BucketInPosLiftDAdcFull [ArmPos] [LiftPos], ie it has its own value for each boom and boom position.

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Claims (14)

PATENT CLAIMS A method of weighing a load in a bucket (12) of an implement (14), the bucket (12) being articulated to the end of at least one boom (18) and the bucket (12) being driven by a bucket cylinder (20) and the boom (18) by a lifting cylinder (22), in which the calibration is performed in the following steps: - determining the first pressure levels (p1) of the bucket cylinder (20) and the lifting cylinder (22) in different positions of the boom (18) with the bucket (12) empty and in the normal position, - determining the bucket cylinder (20) and lifting cylinder (22) ) position-corrected second pressure levels (p2) at different positions of the boom (18) and the bucket (12) both when the bucket (12) is empty and when the bucket is loaded with a load (11) whose center of gravity (g1) in the bucket (12) is known, (20) and the eccentric third pressure levels (p3) of the lifting cylinder (22) in different positions of the boom (18) and the bucket (12) with the bucket (12) loaded with an eccentric load (g2) in the bucket (12) , and a load weighing is performed The load in the bucket (12) is weighed by measuring - the fourth pressure levels O 25 (p4) of the remote cylinder (20) and the lifting cylinder (22) during loading, 5 - the first position information of the position of the boom (18) is determined (al) that the position of the bucket (12) = the second position information (a2), N - is calculated from the first pressure levels, the second pressure levels and the third pressure levels in said boom N (18) position and the bucket (12) position from the bucket (12) position N first change in pressure level (Apl), for both bucket cylinder (20) and lift cylinder (21), with empty and full bucket (12), - on the basis of the first pressure levels (p1), the second pressure levels (p2) and the third pressure levels (p3), the second position due to the asymmetrical position of the load (11) in the bucket (12) in the position of the boom (18) and the bucket (12) is calculated - the change in net level (Ap2) due to both the bucket cylinder (20) and the lifting cylinder (21), a2) for the pressure level of the lifting cylinder (21) by comparing the changes in the first pressure level (Apl) with the change in the third pressure level (Ap3) obtained as the difference between the first pressure level (p1) and the second pressure level (p2), a second correction value (C2) caused by the load (11) for the pressure level of the lifting cylinder (21) by comparing the changes in the scaled second pressure level of the lifting cylinder (21) and the bucket cylinder (20) (s4p2) a, - correcting the measured pressure level of the lifting cylinder (22) by means of said first correction value (C1) and the second correction value (C2) to obtain a corrected weighing result. Method according to Claim 1, characterized in that in calculating the first pressure level change (4pl), the difference between the first pressure levels (p1) and the second pressure levels (p2) is interpolated to all the first N position data ( (al) for both empty and full E buckets (12). 05 3 30 Method according to Claim 1 or 2, characterized in that first pressure levels (pI) of 4 to N 20 are formed at the measuring point of the boom (18), preferably at 8 to 12 measuring points in the operating range of the boom (18). Method according to Claim 1 or 2, characterized in that the first pressure levels (pI) at 3 to 6 measuring points are formed and the intervals between the measuring points are blue-interpolated. Method according to one of Claims 1 to 4, characterized in that the second pressure levels (p2) and the third pressure levels (p3) are formed in the slowest possible boom movement in which the weighing can be carried out. Method according to one of Claims 1 to 5, characterized in that the fifth pressure levels (p5) are determined with the basic machine in the tilted position (a3) and the third correction value (C3) caused by the basic machine position (a3) is calculated for the lifting cylinder (21). as the difference between the first pressure level (p1) and the fifth pressure level (p5). Method according to one of Claims 1 to 6, characterized in that the sixth pressure levels (p6) are determined with the boom (18) in lateral movement and the fourth correction value (C4) caused by the lateral movement of the boom (18) is calculated for the lifting cylinder (21). as the difference between the first pressure level (pl) and the sixth pressure level (p6). Method according to one of Claims 1 to 7, characterized in that the seventh pressure levels (p7) N when using the boom (18) with the lifting cylinder (22) are determined and the fifth correction value (C5) caused by the movement of the boom (18) is calculated. to the pressure level of the tosylinder (21) as the difference between the first pressure level (p1) and 3 30 the seventh pressure level (p7). S Method according to one of Claims 1 to 8, characterized in that the working machine (14) is an excavator (100) and the boom (18) comprises both a lifting boom (40) and a transfer boom (42) and both calibration and measurement are performed on all lifting booms (18). 40) and the transfer boom (42). Method according to one of Claims 1 to 9, characterized in that second pressure levels (p2) and third pressure levels (p3) are formed at a measuring point of 4 to 20 booms (18), preferably at 8 to 12 measuring points in the operating range of the boom (18). Method according to one of Claims 1 to 10, characterized in that in calculating the change in the second pressure level (4p2), the third pressure level (p3) is interpolated to all positions of the load (11) in the bucket (12). Method according to one of Claims 1 to 11, characterized in that the first position information (α1) of the position of the boom (18) is continuously compared with the to the position point values of the boom (18) contained in the calibration tables and determining the value of the pressure of the lifting cylinder (22) from the calibration table according to the position point values. A weighing system (10) for a working machine (14) provided with a bucket (12), the working machine (14) comprising a frame O 25 (16), at least one boom (18) articulated to the frame (16) for hanging said bucket (12), a bucket cylinder N (20) driving the bucket (12) and a lifting cylinder (22) driving the boom (18), wherein the system (10) comprises an N - first pressure sensor (24) for measuring the pressure of the lifting cylinder (22) and the first pressure data - a second pressure sensor (26) for measuring the pressure of the bucket cylinder (20) and for generating a second pressure information (pO 2), - a first position sensor (28) for determining the position of the boom (18) and for generating a first position information (a1), - a second position sensor (30) for determining the position of the bucket (12) and for generating a second position information (a2), = a central processing unit (32) comprising a memory (34), a calculation unit (36) and software means (38) for performing weighing calculations, and - data transmission means (45) for the first pressure information (p01), the second pressure information (p02), the first position information (al) and for transmitting the second position information (a2) to the central processing unit (32), characterized in that the memory (34) stores - the first pressure levels (p1) of the bucket cylinder (20) and the lifting cylinder (22) at different positions of the boom (18) when empty - second pressure levels (p2) in different positions of boom (18) and bucket (12) with bucket (12) loaded with a load of known center of gravity (gl), and - third pressure levels (p3) of boom (18) and bucket ( 12) in different positions, the bucket (12) being loaded with an eccentric load (11), the center of gravity (g2) of which in the bucket (12) is known, and said software means (38) are adapted to: - calculate, on the basis of the first pressure levels, - the second pressure levels and the third pressure levels, the change in the first pressure level (Apl) due to the position of the bucket (12) in said boom position O 25 (18) and bucket (12) position, and N for the bucket cylinder (20) that for the lifting cylinder (21), with the empty = and full bucket (12), N - to calculate the N min (18) on the basis of the first pressure levels (p1), the second pressure levels (p2) and the third pressure levels (p3) in the position (a2) of the bucket (12), the change in the second pressure level (4p2) due to the asymmetrical position N of the load (11) in the bucket (12) due to both the bucket cylinder (20) and the lifting cylinder (21), - to scale the change in the second pressure level (4p2) to form a change in the second pressure level (sAp2) scaled to the load used in the calibration, - to calculate the first correction value (C1) of the bucket (11) (Apl) the change in the third pressure level (4p3) obtained as the difference between the first pressure level (p1) and the second pressure level (p2) of the calibration, the scaled second pressure level changes (s4p2) of the lifting cylinder (21) and the bucket cylinder (20) to each other, - correcting the measured pressure level of the lifting cylinder (22) to obtain a weighed result corrected by said first correction value (C1) and the second correction value (C2). A working machine (14) comprising a frame (16), a bucket (12), at least one boom (18) articulated to the frame (16) for hanging said bucket (12), a bucket cylinder (20) driving the bucket (12), a boom (18) a lifting cylinder (22) and a weighing system (10) comprising - a first pressure sensor (24) for measuring the pressure of the lifting cylinder (22) and generating a first pressure data (p01), - a second pressure sensor (26) ) for measuring the pressure 5 of the bucket cylinder (20) and generating a second pressure information (pO 2), N - a first position sensor (28) for determining the position of the boom (18) and generating a first position information (a1), N - a second position sensor (30) for generating the bucket (12) ) for determining the position and generating the second position information (a2), N - a central processing unit (32) comprising a memory (34), a calculation unit (36) and software means (38) for performing the weighing calculation, and - communication means (45) for transmitting the first pressure information (p01), the second pressure information (p02), the first position information (a1) and the second position information (a2) to the central processing unit (32), characterized in that a - bucket cylinder (20) and the first pressure levels (p1) of the lifting cylinder (22) in different positions of the boom (18) with the bucket (12) empty - the second pressure levels (p2) of the different positions of the boom (18) and the bucket (12) with the bucket (12) loaded with a load the point (gl) is known, and - third pressure levels (p3) in different positions of the boom (18) and the bucket (12) with the bucket (12) loaded with an eccentric load (11), the center of gravity (g2) of the bucket (12) being known, and said software means (38) are adapted to: - calculate, on the basis of the first pressure levels, the second pressure levels and the third pressure levels in said boom (18) position (a1) and bucket (12) position (a2) the first change in pressure level due to bucket (12) position (Apl), as well as a bucket cylinder (20) that the lifting cylinder (21), with the empty and full bucket (12), - on the basis of the first pressure levels (p1), the second pressure levels (p2) and the third pressure levels (p3) - and in the position (a2) of the bucket (12), a second change in the pressure level (Ap2) due to the asymmetrical position of the load O 25 (11) in the bucket (12) due to both the bucket cylinder (20) and the lifting cylinder (21), = - scale the second pressure level change (Ap2) to form a change in the second pressure level (s4p2) 3 30 scaled to the load used in the calibration, N - calculate the first correction value (Cl) caused by the position (a2) of the bucket (11) - guaranteeing the changes of the first pressure level (Apl) to the change of the third pressure level (4p3) obtained as the difference between the first pressure level (p1) and the second pressure level (p2) of calibration, pressure level by varying the scaled second pressure level (s4p2) of the lifting cylinder (21) and the bucket cylinder (20), to correct the measured pressure level of the lifting cylinder (22) to obtain a weighed result corrected by said first correction value (C1) and the second correction value (C2). 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