Automatic System for Monitoring the Mixing of Conglomerates

• US 20090171595A1
• Filed: 11/17/2006
• Published: 07/02/2009
• Est. Priority Date: 11/28/2005
• Status: Active Grant

• Current Assignee: Antonio Ozamiz Tapia
• Original Assignee: Antonio Ozamiz Tapia, Javier Ozamiz Tapia
• Inventors: Bonilla Benegas, Eugenio
• Granted Patent: US 9,833,928 B2
• Time in Patent Office: Days
• US Class Current: 702/41
• CPC Class Codes: B01F 35/213 of the properties of the mixtures, e.g. temperature, density or colour
• CPC Class Codes: B01F 35/2136 Viscosity
• CPC Class Codes: B28C 5/422 Controlling or measuring devices B28C5/4227 takes precedence
• CPC Class Codes: B28C 7/02 Controlling the operation of the mixing
• CPC Class Codes: B60P 3/16 for carrying mixed concrete, e.g. having rotatable drums concrete-mixing apparatus specially adapted for being mounted on vehicles with provision for mixing during transport B28C5/42
• CPC Class Codes: G08G 1/20 Monitoring the location of vehicles belonging to a group, e.g. fleet of vehicles, countable or determined number of vehicles

Abstract

The invention relates to an automatic system for monitoring the mixing of conglomerates. The inventive system can be used to monitor and measure the volume of a conglomerate, i.e. a concrete, mortar or other similar product, and the conditions in which the conglomerate is being mixed inside a mixer. The invention is characterised in that the system is provided with a sensor which rotates integrally with the mixer and which is fitted with a blade that is sensitive to the stresses exerted by the conglomerate thereon. The invention is also characterised in that the aforementioned information is transmitted to one or more terminals, by means of radio communication or other similar wireless communication means, for use in industrial processes.

Claims

1. System for detecting the direction of rotation in mixers, the speed of rotation in mixers, the volume of concrete mix contained in the mixer and the plasticity of the concrete mix inside the mixer and for automatically identifying the mixer, characterized in that it has a sensor which is installed integrally with the mixer so as to rotate together therewith and which performs the functions mentioned, analysing the forces acting on the blade with which it is provided, during its interaction with the concrete mix existing inside the mixer, transmitting all this information to other terminal devices by means of a wireless communications system.

2. System according to claim 1, characterized in that it provides a second method in addition to the previous method for detecting the direction of rotation of the mixer and the speed of rotation of the mixer using a set of accelerometers in the three spatial dimensions, thereby making the entire system more reliable and capable of automatically detecting exceptional or fault conditions if the two detection mechanisms do not indicate the same conditions as regards direction of rotation.

3. System according to claim 1, characterized in that it provides a method for being able to deduce that the mixer contains no concrete when it is detected via the accelerometers that it is rotating, but there is no significant variation in the force acting on the blade.

4. Algorithm for a system according to claim 1, characterized in that it allows calculation of the revolutions and the direction of rotation of a mixer by analysing the force signal over time acting on the blade of its sensor, based on determining its periodicity over time, and the force values with respect to a reference value for the force in the rest condition.

5. Algorithm for a system according to claim 1, characterized in that it allows calculation of the revolutions and direction of rotation using a set of the accelerometers of the sensor.

6. Method for a system according to claim 1, characterized in that it is possible to deduce the volume of concrete mix transported and its plasticity based on identification of the contact angle and banking angle as intermediate variables said angles being able to be automatically calculated.

7. Algorithm for a system according to claim 1, characterized in that it allows calculation of the contact angle (β

) and the banking angle (φ

) of the blade with the concrete mix by analysing the signal for the force acting on the blade over time and correlating this information with the evolution of the sensor in the plane YZ obtained from the signals supplied by a number of accelerometers available to the sensor that continually detects from the analogue/digital converter the signal of the Wheatstone bridge, which is proportional to the force acting on the blade, and filters the readings and assigns them to time instants, obtaining a table of force values over time of magnitude “

n”

;

wherein for each new reading, the oldest value is discarded and the latest one is stored. In turn, the spatial position xyz supplied by the accelerometers is stored in another table;

using all these sample readings taken at preassigned time instants, it is determined when there is a significant drop in the signal for the force applied to the blade (loss of contact of the blade with the concrete mix) and when there is a renewed increase in the force (renewed contact of the blade with the concrete mix) the algorithm is being described in more detail below;

Assuming “

i”

is an instant for detecting values on the A/D channel and on the accelerometers, occurring every “

mi”

milliseconds;

Assuming “

t”

is a sampling time occurring every “

mt”

milliseconds;

Assuming “

m”

is the number of readings taken for each sampling time so that mt=mi×

m;

Assuming “

n”

is the number of sample values stored in the memory;

Then;

For a calculation period p, the angular velocity at which the mixer (ω

) is rotating is calculated, characterized in that it allows calculation of the revolutions and the direction of rotation of a mixer by analysing the force signal over time acting on the blade of its sensor, based on determining its periodicity over time, and the force values with respect to a reference value for the force in the rest condition;

Depending on the value of (ω

), mi, m and n are suitably defined so as to record historical information for various revolutions of the mixer;

mi=Pm(ω

)

m=Dm(ω

)

n=Dn(ω

)

where Pmi( ) is a function which determines the sampling period depending on the value of ω

, and Dm( ) and Dn( ) are functions which define m and n depending on the value of ω

;

memory in the system is reserved depending on m and n;

for each time period “

mi”

the value of the A/D channel and the accelerometers for the instant “

i”

is detected;

f=force acting on the blade, via the A/D channel connected to the strain-gauge strips;

xyz=spatial position xyz of the set of accelerometers (there may be one or more accelerometers in the system), deducing this position with respect to a reference point, depending on the spatial acceleration which has occurred in a time period “

mi”

;

the sample values for the force and position at the instant “

i”

are stored in the tables for the force sample values MF[ ] and position sample values MP[ ];

MF[i]=f

MP[i]=xyz

i=i+1

If i=m, then i=0

for each time period “

mt”

, the sample readings for the time instant t are taken, applying a software filter, and a statistical value for the force in the period t and the position xyz in the period t is obtained, using the sample values m of f and xyz previously stored;

Ft=SamplesFilterF(MF)

Pt=SamplesFilterP(MP)

and they are stored in the force sample values table TM[ ] and in the position sample values table TMP[ ];

TMF[t]=Ft

TMP[t]=Pt

T=t+1

If t=n, then t=0;

the gradient is applied to the values in the table TMF, obtaining the gradients table gTMF;

gTMF=grad(TMF)

the indices of minimum and maximum values of gTMF are obtained;

iMin[ ]=MinV(gTMF)

then position table TMP is accessed with these indices in order to obtain the co-ordinates of y and z in these instants;

and for each of them;

xyz=TMP[iMin]

yMin=CoY(xyz)

zMin−

CoZ(xyz)

xyz=TMP[iMax]

yMax=CoY(xyz)

zMax−

CoZ(xyz)

then, for each pair of minimum force values of z and y and consecutive pair of maximum force values;

β

+φ

=tan gentarc(zMin/yMin)

π

−

β

+φ

=tan gentarc(zMax/yMax)

so that by solving these system of two equations with two unknown variables, a sample value of the contact angle β and

another sample value of the banking angle φ

are obtained;

and as already mentioned, there also exist other forces in the system such as the longitudinal forces forwards during mixing and backwards during discharging and the associated inertial forces due to the dynamics of the moving lorry, it is necessary to apply the statistical process to each pair (β

, φ

) in order to discard the values which have been falsified by said movements, applying the sampling theory and thus obtaining the definitive values.

8. Algorithm for a system according to claim 7, characterized in that it allows calculation of the volume of concrete mix present in the mixer based on the correlation which exists between that volume and the angular velocity at which the mixer rotates (ω

), the contact angle (β

) and the banking angle (φ

). For this purpose the algorithm involves calculating firstly the angular velocity (ω

), characterized in that it allows calculation of the revolutions and the direction of rotation of a mixer by analysing the force signal over time acting on the blade of its sensor, based on determining its periodicity over time, and the force values with respect to a reference value for the force in the rest condition and then calculating the contact angle (β

) and the banking angle (φ

), then segmenting the values obtained for (ω

), (β

) and (φ

) so as to classify them in value ranges and, using all these ranges or some of them, accessing a table programmed in the memory, whichever one it may be, or in a database which may exist in the computer where the algorithm is performed or in any other server equipment accessed to obtain this information and in this way obtain the volume of the concrete mix.

9. Algorithm for a system according to claim 7, characterized in that it allows calculation of the plasticity of the concrete mix existing in the mixer, based on the correlation which exists between that plasticity and angular velocity at which the mixer rotates (ω

), the contact angle (β

) and the banking angle (φ

). For this purpose the algorithm involves calculating firstly the angular velocity (ω

), characterized in that it allows calculation of the revolutions and the direction of rotation of a mixer by analysing the force signal over time acting on the blade of its sensor based on determining its periodicity over time, and the force values with respect to a reference value for the force in the rest condition and then calculating the contact angle (β

), characterized in that it is possible to deduce the volume of concrete mix transported and its plasticity based on identification of the contact angle and banking angle as intermediate variables said angles being able to be automatically calculated, and then calculating the raised angle (φ

), then segmenting the values obtained for (ω

), (β

) and (φ

) so as to classify them in value ranges and, using all these ranges or some of them, accessing a table using them as indices, in order to obtain from said table a tabulated plasticity value, said table being able to be programmed in the memory, whichever one it may be, or in a database of the computer where the algorithm is performed or in any other server equipment to which the processor may be connected in order to access said table.

10. System according to claim 1, characterized in that it is able to transmit via a wireless communications system without a physical connection the information relating to the direction of rotation of the mixer of the mixer lorry to other devices which may be installed in the associated lorry or on the outside thereof.

11. System according to claim 1, characterized in that it is able to transmit via a wireless communications system without a physical connection the information relating to the speed at which the mixer of the mixer lorry is rotating to other devices which may be installed in the associated lorry or on the outside thereof.

12. System according to claim 1, characterized in that it is able to transmit via a wireless communications system without a physical connection the information relating to the volume of concrete mix which the mixer lorry is transporting to other devices which may be installed in the associated lorry or on the outside thereof.

13. System according to claim 1, characterized in that it is able to transmit via a wireless communications system without a physical connection the information relating to the plasticity of the concrete mix present in the mixer of the mixer lorry to other devices which may be installed in the associated lorry or on the outside thereof.

14. System according to claim 1, characterized in that it is able to transmit via a wireless communications system without a physical connection the information relating to the identifier of the lorry or the mixer of the mixer lorry to other devices which may be installed in the associated lorry or on the outside thereof.

15. System according to claim 1, characterized in that it provides a telematic means for measuring the plasticity, called “

remote plasticity meter”

, for transmitting the information relating to the plasticity via a wireless communication means to any equipment for metering and producing the concrete mix via the factory terminal. For this purpose the drums sensor transmits the information to the factory terminal which in turn re-transmits it by any other type of wired or wireless means to the metering equipment at the factory or to any other device at the factory where said information is displayed, providing it with a remote measurement of the plasticity.

16. Lorry viewer system, characterized in that, in combination with the system according to claim 1, it allows any person concerned, and in particular the customer receiving the concrete mix transported by the lorry, the possibility of checking the volume of the concrete mix existing inside the drum thereof, by observing the screen on which this information is displayed.

17. System according to claim 16, characterized in that it allows, in combination with the system according to claim 1, any person concerned, and in particular the customer receiving the concrete mix transported by the lorry, the possibility of checking the plasticity of the concrete mix existing inside the drum thereof.

18. Factory terminal system, characterized in that it allows, in combination with the system according to claim 1, the possibility of providing the metering and production system with a telematic measurement of the plasticity of the concrete mix via a wireless connection, during the course of manufacture, improving the production process by ensuring the appropriate plasticity of the concrete mix which is being manufactured at that moment.

19. System according to claim 18, characterized in that it allows automatic detection of the quantity of concrete mix which the lorry is returning to the plant and communication of this information, via a wired or wireless communications port to the metering and production system, so that this information may be taken into account for the next load to be prepared for this lorry.

20. Customer terminal system, characterized in that it allows, in combination with the system according to claim 1, the possibility of offering the customer an information-processing means so that the customer is able to check the volume of the concrete mix which is being delivered and its plasticity.

21. System according to claim 20, characterized in that it allows the possibility of measuring automatically and telematically the level of satisfaction of the customer with regard to the quality of the product which is being delivered to them.

22. System according to claim 20, characterized in that it allows the possibility of measuring automatically and telematically, the level of satisfaction of the customer with regard to the quality of service provided by the driver of the lorry delivering the concrete mix to them.

23. System according to claim 20, characterized in that it allows the possibility for the customer to accept automatically and telematically the concrete mix which is being supplied to them.