Automatic system for monitoring the mixing of conglomerates

• US 9,833,928 B2
• Filed: 11/17/2006
• Issued: 12/05/2017
• 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
• Primary Examiner(s): PARK, HYUN D
• Application Number:
  US12/085,471
• Publication Number:
  US 20090171595A1
• Time in Patent Office: 4,036 Days
• Field of Search: 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 characterized 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 characterized 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. A system for monitoring a plasticity and a volume of a mixture being mixed inside a rotatory mixer, wherein the mixture regards to concrete mixes, wherein the volume regards to a cubic capacity of whole said mixture as measured in cubic units, and wherein said system comprises:

a sensor which is installed integrally to said mixer through a simple longitudinal cut and which is fitted with strain-gauge strips which are connected in the form of a Wheatstone bridge, so as to act as a load cell;

said bridge is connected to an analog/digital converter by which a cyclical signal is acquired over time as digital information, hereinafter called a force signal (F), and which can be broken down into one part of the rotation during which the sensor is subject to a force and into another part of the rotation where the sensor is not subject to said force;

one or more accelerometers operating in the three spatial dimensions or XYZ axes, by which an angular position and an angular velocity (ω

) of the system is identified at any instant, which includes identifying an angular position of the system at an instant in which the sensor no longer makes contact with the mixture when said mixture is in a rest condition, hereinafter called contact angle (β

), and an angular position of the system at an instant in which the sensor no longer makes contact with the mixture during mixing at an angular velocity (ω

), hereinafter called banking angle (φ

);

said system autonomously detects the volume of said mixture, from its correlations with the contact angle (β

) and a percentage of a cycle in said force signal (F) subject to said force, and the plasticity of said mixture, from its correlations with the force signal (F) and the banking angle (φ

), over time during an interaction of the sensor with all layers of said mixture; and

wherein said system further comprises a short-distance wireless series communication controller by which said system transmits resulting digital information of the volume of said mixture, the plasticity of said mixture, and an unique identifier of said sensor, to other devices, enabling precise corrections in said mixture to be made until specific requirements of said plasticity and said volume are detected by said system.

2. The system according to claim 1, wherein the system further detects a revolution of the sensor along the YZ axes whenever Z or Y passes through a maximum point or passes through a minimum point.

3. The system according to claim 2, wherein the system further detects that the mixer contains no mixture when it is detected via the accelerometer or accelerometers that it is rotating, but there is no significant variation in a force acting on the sensor.

4. A method for a system according to claim 2, said method recording, using a microprocessor, the contact angle (β

) and the banking angle (φ

) as digital variables.

5. A method for a system according to claim 2, said method deducing, using a microprocessor, the volume of said mixture and the plasticity of said mixture as digital variables based on the contact angle (β

) and the banking angle (φ

).

6. A non-transitory computer readable medium containing an algorithm stored therein for causing a computer processor to perform for a system according to claim 2, wherein the algorithm calculates the contact angle (β

) and the banking angle (φ

) of the sensor with the mixture by continuously acquiring a reading from an analog/digital converter that is analyzing a signal of a Wheatstone bridge, which is proportional to a force acting on the sensor, over time to obtain digital information of each reading, and correlating said information with the evolution in the angular position of the sensor in a plane YZ obtained from signals supplied by a number of accelerometers available to die sensor, and filters die readings and assigns them to time instants, obtaining a table of force values over time of size “

n”

;

wherein for each new reading, the oldest value is discarded and the latest one is stored, and in turn, a 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 die force applied to the sensor (loss of contact of the sensor with the concrete mix) and when there is a renewed increase in the force (renewed contact of the sensor with the concrete mix), the algorithm is described in more detail below;

assuming “

i”

is an instant for detecting values on an ND 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 a memory;

then;

for a calculation period p, an angular velocity (ω

) at which the rotatory mixer is rotating is calculated, characterized in that it calculates the revolutions and the direction of rotation of a mixer by analyzing the force signal over time acting on the 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 the angular velocity (ω

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

mi=Pmi(ω

)

m=Dm(ω

)

n=Dn(ω

)

where Pmi(ω

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

, and Dm(ω

) and Dn(ω

) are functions which define m and n depending on the value of ω

;

a memory in the system is allocated depending on m and n;

for each time period “

mi”

the value of the ND channel and die accelerometers for the instant “

i”

is detected;

f=force acting on the sensor, 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 die system), deducing this position with respect to a reference point, depending on the spatial acceleration which has occurred in a time period “

ini”

;

sample values for the force and position at the instant “

i”

are stored in the tables for the force sample values MI-′

QJ and position sample values MP[i];

MF[i]=f

MP[i]=xyz

i=i+1

If i equals 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)

Ft=SamplesFilterP(MP)

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

TMF[t]=Ft

TMP[t]=Pt

t=t+1

If t equals 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[i]=MinV(gTMF)

iMax[i]=MaxV(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

=tangentarc(zMin/yMin)

π

+β

+φ

=tangentarc(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 there also exist longitudinal forces forwards during mixing and backwards during discharging and associated inertial forces due to dynamics of the moving lorry, applying statistical process to each pair (β

, φ

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

7. A non-transitory computer readable medium containing an algorithm stored therein for causing a computer processor to perform for a system according to claim 2, wherein the algorithm calculates the volume of mixture present in the mixer based on the correlation which exists between that volume and the angular velocity (ω

) at which the mixer rotates, the contact angle (β

) and the banking angle (φ

);

for this purpose the algorithm involves calculating firstly the angular velocity (ω

), characterized in that calculates a revolution and a direction of rotation of a mixer by analyzing the force signal over time acquired on the sensor, based on determining its periodicity over time, and force values with respect to a reference value for force in the rest condition and then calculating the contact angle (β

) and the banking angle (φ

), then segmenting values obtained for (ω

), (β

) and (φ

) so as to classify them in value ranges and, using at least some of these ranges, accessing a table programmed in a memory or in a database which may exist in a 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 die concrete mix.

8. A non-transitory computer readable medium containing an algorithm stored therein for causing a computer processor to perform for a system according to claim 2, wherein the algorithm calculates the plasticity of the mixture existing in the mixer, based on the correlation which exists between that plasticity and angular velocity (ω

) at which the mixer rotates, 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 calculates a revolution and a direction of rotation of a mixer by analyzing the force signal over time acquired on the sensor, based on determining its periodicity over time, and force values with respect to a reference value for force in the rest condition and then calculating the contact angle (β

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

), then segmenting values obtained for (ω

), (β

) and (φ

) so as to classify them in value ranges and, using at least some of these ranges, 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 a memory or in a database of a 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.

9. The system according to claim 2, wherein said system transmits via the short-distance wireless series communications controller without a physical connection digital information relating to a direction of rotation of the mixer of a mixer lorry to other devices which are installed in the associated lorry or on an outside thereof.

10. The system according to claim 2, wherein said system transmits via the short-distance wireless series communications controller without a physical connection digital information relating to a speed at which the mixer of a mixer lorry is rotating to other devices which are installed in the associated lorry or on an outside thereof.

11. The system according to claim 2, wherein said system transmits via the short-distance wireless series communications controller without a physical connection digital information relating to the volume of mixture which a mixer lorry is transporting to other devices which are installed in the associated lorry or on an outside thereof.

12. The system according to claim 2, wherein said system transmits via the short-distance wireless series communications controller without a physical connection digital information relating to the plasticity of the mixture present in the mixer of a mixer lorry to other devices which are installed in the associated lorry or on an outside thereof.

13. The system according to claim 2, wherein said system transmits via the short-distance wireless series communications controller without a physical connection digital information relating to the unique identifier of said sensor to other devices which are installed in the associated lorry or on an outside thereof.

14. The system according to claim 2, providing a wireless communication for measuring the plasticity, called a “

digital remote plasticity meter”

, fur transmitting digital information relating to the plasticity via the short-distance wireless series communication controller to equipment for metering and producing the concrete mix via a factory terminal;

for this purpose said system transmits an information to the factory terminal which in turn re-transmits said information by wired or wireless links to the metering equipment at the factory where said information is displayed, providing it with a remote measurement of the plasticity.

15. A lorry viewer system, in which, in combination with the system according to claim 2, said lorry viewer system is installed in a visible part of the lorry and allows a customer receiving the mixture transported by a lorry to check an information of the volume of the mixture existing inside a drum thereof, by observing a screen on which said information is displayed.

16. The system according to claim 15, wherein said system allows a customer receiving the concrete mix transported by a lorry to check an information of the plasticity of the mixture existing inside a drum thereof.

17. A factory terminal system providing, in combination with die system according to claim 2, a metering and production system with a telematic measurement of the plasticity of the mixture via a wireless connection to the short-distance wireless series communications controller, during the course of manufacture, improving a production process by ensuring an appropriate plasticity of the mixture which is being manufactured at that moment.

18. The system according to claim 17 providing automatic detection of a quantity of mixture which a lorry is returning to a plant and communication of information related thereto, via a wired or wireless communications port to a metering and production system, so that said information may be taken into account for a next load to be prepared for said lorry.

19. A customer terminal system, providing, in combination with the system according to claim 2, a customer with an interactive information-processing system for telematically checking the volume of the mixture which is being delivered and its plasticity wherein it provides to said customer said interactive information-processing system for telematically providing a level of satisfaction regarding said delivery, said customer terminal system is based on either a custom electronic design, based on a short-distance wireless communications controller, or in the use of a standard wireless electronic device as a Smartphone or a PDA, property of said customer, and which provides said interactive information-processing system.

20. The system according to claim 19, wherein said system automatically and telematically measures a level of satisfaction of a customer with regard to a quality of a product which is being delivered to the customer.

21. The system according to claim 19, wherein said system automatically and telematically measures a level of satisfaction of a customer with regard to a quality of service provided by a driver of a lorry delivering the mixture to the customer.

22. The system according to claim 19, wherein a customer is requested to accept automatically and telematically the mixture which is being supplied to the customer.

23. A method for a system according to claim 1, said method autonomously recording at any moment, using a microprocessor, a revolution and a direction of rotation of the sensor as digital variables by analyzing the force signal acquired on the sensor, based on determining its periodicity over time, and the force signal values with respect to a reference value for the force signal in the rest condition.